a study published by the University of Wisconsin in July, 2019, scientists discovered that a rapamycin analog called DL001 inhibits mTOR without all the severe side effects, such as suppression of the immune system, glucose, or liver toxicity. Suppression of mTOR has been associated with better health and longer life. mTOR is activated by eating foods like red meat, so finding a way to suppress mTOR without all the harmful side effects would be a major breakthrough.

Scientists have known that mTOR is composed of two complexes, called mTORC1 and mTORC2. As it turns out, you only need to suppress one of them, mTORC1 to get all the positive longevity benefits associated with rapamycin. Suppressing mTORC2 is what has caused many of the negative side effects of rapamycin, so discovering that the rapamycin analog DL001 suppresses mTORC1 without suppressing mTORC2 is the breakthrough that may finally allow us to get the benefits of rapamycin without the severe side effects.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6642166/