KIT and gastrointestinal stromal tumor: Imatinib, a small molecule inhibitor originally developed to target BCR-ABL in chronic myeloid leukemia but whose kinase inhibition extends to cKIT, has dramatically improved survival outcomes in both early-stage and advanced GIST,(Rajendra et al., 2013) whilst unprecedented response rates were seen in PEComa in case series treated with sirolimus, an inhibitor of the mTOR complex used in the prevention of organ transplant rejection.(Benson et al., 2014)