MTOR and lymphangioleiomyomatosis: The drug Sirolimus (also known as rapamycin; trade name is Rapamune, Pfizer Inc., New York City, NY, USA), which is an inhibitor of the kinase mTOR (mTOR is also known as a mammalian target of rapamycin and is a component of the mTORC1 signaling complex that can be regulated by TSC1 and TSC2 [50]), is now used to treat LAM and can stabilize lung function over many years of therapy while producing a sustained reduction of VEGF-D levels [51,52].