As an anti-aging drug, the secret of rapamycin's longevity lies in its ability to block the mTOR channel-one of the "master switches" that controls the process of affecting cell growth and reproduction. When food is abundant, this channel changes from hormones and nutrition The signal obtained in the substance causes cells to absorb nutrients and grow, but the process of metabolism and growth of cells will produce by-products that stimulate cell aging; when the intake of food calories is restricted, this channel can send signals to stop cells from growing, thereby To delay aging. Rapamycin is probably the most effective anti-aging drug found so far. Which of the following, if true, does not support the above conclusions:. ['Rapamycin is used to treat certain cancers because of its inhibitory effect on cell growth.', 'Experimental studies have shown that rapamycin can extend the lifespan of yeast, worms and fruit flies.', 'Rapamycin makes people more vulnerable to bacteria and viruses while delaying aging.', 'Rapamycin can block mTOR channels without limiting food calorie intake.']