TSC1 and cancer: In light of the recent discovery of hamartin being a client and co-chaperon of Hsp90, the role of this interaction in rapamycin resistance would be worth exploring; increased Hsp90 expression has been linked to EMT in a variety of cancers49–51 Although Hsp90 is inhibited by rapamycin52, Hsp90 inhibitors synergize with rapamycin to induce cancer cell apoptosis53 possibly through activation of ER stress.