MTOR and Hutchinson-Gilford progeria syndrome: Remarkably, the drug rapamycin (sirolimus) inhibits mTOR activity to levels allowing for reconstitution of a cell's autophagic capacity, clearance of progerin and other debris and prevention or reversal of geroconversion in cells from HGPS patients [44, 88], and also in non-HGPS mammalian cells [89].