In 2009, Nature magazine had published several theses on sirolimus.

A group of scientists separated nearly 2,000 twenty-month-old white mice which were the equivalent of a sixty-year-old human into two groups. One of the groups was fed with food mixed with sirolimus.

The results of the experiment proved to be rather surprising. The average lifespan of the group of mice which ingested sirolimus displayed an increase of 14% over the other group.

In the last century, scientists discovered two methods for prolonging the lifespan of mammalian species. The first method is by “repairing” the genes while the second method was by monitoring their diet, lowering their fat intake.

Needless to say, the gene repairing solution was only viable with the a.s.sistance of devices like the Medpod 3000.

The purpose of reducing fat intake was to minimize the activation of a protein molecule known as TOR.

TOR was a signal molecule naturally produced by the human body. Its purpose was to regulate the growth of each cell of the eukaryotes. When TOR was activated, it caused the cells to synthesize biomolecules. This increased the ma.s.s and volume of the cells and also synthesized protein and nucleic acid which led to the cells growing bigger and heavier.

a.s.sume the human body was a piece of intricate, large machinery. Even if energy could be infinitely drawn from its surroundings, each “component” of the machine would still experience wear and tear over the years. What the activation of TOR did apart from fulfilling the basic needs of life was essentially overclocking the components, causing the machine to age at a faster rate.

The reason sirolimus was able to extend the lifespan of the mice was very likely due to it “deceiving” the body of the mice, leading them to believe that there was a lowered intake of fats.

With that said, all of these data were not supported by a proper human clinical trial. All of the applications for conducting a clinical trial on sirolimus' effects of prolonging human lifespan were rejected by the officials.

Nevertheless, in the duration between 2010 to 2020, there were still the occasional rumors of doctors secretly taking sirolimus.

However, after a decade had pa.s.sed, the theory of sirolimus being a “life-extending drug” was once again debunked.

Clinical Medicine Journal had published a thesis in April of 2020 stating that severely decreased TOR activity may lead to accelerated aging of the hematopoietic system.

Simply put, at a cellular level, inhibiting TOR may deceive the body and in turn, slow down the aging process of the human body. However, the hematopoietic system required TOR activity to sustain itself.

Too much inhibition of TOR directly contributed to the aging of the cell niches in the bone marrow, which led to the aging of hematopoietic stem cell function. It was simply a 'd*mned if you do, d*mned if you don't' situation.

In truth, Chen Chen had once considered modifying sirolimus or using a combination of drugs to counteract its side effects to procure a specialized drug for prolonging lifespan.

Later, Chen Chen realized the greater potential in the stem cells sector and how much more impact it had on the human body compared to sirolimus. Therefore, he gave up on the idea of using sirolimus and s.h.i.+fted his focus onto stem cells, which finally led to the birth of the age-reversal treatment project.

Now, facing the problem of immunosuppression, Chen Chen once again thought of this fabled drug. It was Groundhog Day all over again.

Over the next half month, Chen Chen selected a clone which he provided with sirolimus, cyclosporine A, and FK506 daily. The three drugs used in combination soon completely suppressed the immune system of the clone.

After the immune system of the clone had been compromised, Little X extracted the clone and put it on a stretcher.

This time, the clone was no longer injected with T-002. After two past failures, it was now injected with a newly modified T-003.

As expected, despite the clone having its immune system completely suppressed, it easily broke the previous record of three hours and twenty-eight minutes set by the previous clone. After being injected with the virus, it remained alive for a whole six hours.

Apart from that, as there were monumental changes ongoing inside the clone's DNA, Little X was continuously injecting great amounts of nutrients such as glucose and carbohydrates into the clone. This was to prevent the clone from dying from lack of nutrients before it could even succ.u.mb to the T-virus.

From where Chen Chen was, the clone was almost like a rapidly fermenting steamed bun constantly growing in size. It soon reached a height of two meters. Its body intertwined in nerves and muscles like a tyrant of a smaller size.

This was the first time both Chen Chen and Little X had encountered such a situation.

However, the clone still ended up dying in the end. His body was ultimately unable to handle the modification of the T-virus. Still, him surviving eight hours was a notable achievement on its own.

Chen Chen saw a glimpse of hope from this extended time of sustenance.

Chen Chen evaluated intently when he saw the clone which ultimately became zombified anyway. “Despite the result, this was a very productive and meaningful experiment.”

“Yes, there's no problem with the direction we're taking.”

Little X commented while controlling the Black Knights to collect DNA samples from the clone, “Sirolimus can effectively limit the body's adverse reaction to the T-virus. In usual cases, this method of inhibiting the immune system should be lethal as the average human body doesn't have the immunity to combat the T-virus. Inhibiting the immune system may only hasten the death of the host.

“However, the results are completely different if the T-virus is compatible with the DNA of the host.”

With that, Little X compared the DNA between Chen Chen's tyrant clone and the DNA of the latest zombified clone. “Look, we're getting closer to the answer. However, we only have one last matured clone left. The next batch of new clones will need another six months before reaching maturity.”

Little X began sounding frustrated. “The closer the modified T-virus inches toward the formula, the slower the progress will be.”

“That's normal.”

Chen Chen nodded7. “It's just like a game. When you fix a bug, it'll inevitably generate a new bug. Although the code can be continuously revisited to bring the game closer to perfection, as the game becomes more polished, the difficulty of fixing bugs should increase invariably as well. These are all interconnected factors…”

“Which means that at the end of the day, it's still a matter of luck?”

Little X asked.

Chen Chen nodded before sighing. “It's just like when we initially modified the Progenitor virus into a perfected T-virus, there's the luck factor at play one way or another. In the case of many specialized drugs in the world, they weren't specifically developed to treat a specific disease but instead were essentially a product of chance.

“You could argue to a certain extent that… Luck is inherently a part of scientific research, this is completely inevitable. However, the effort and proficiency of the personnel involved may lower the margin.

“Besides, luck may not be on our side forever, but with great effort and skill…”

Chen Chen thought about it for a moment before fixing his statement. “Of course, money works too.”

Little X, “…”