Explaining the mutual exclusivity between TSC1/2 inactivation and MiT/TFE gene rearrangements in PEComas, we and others have previously shown that mTORC1 activation leads to constitutive activation of TFEB and TFE3 through FLCN inactivation19,20. The gene discussed is TFE3; the disease is neoplasm with perivascular epithelioid cell differentiation.