They belong to the family of mesenchymal tumors and include angiomyolipomas, clear cell sugar tumors of the lung, and PEComas not otherwise specified (NOS). Tuberous sclerosis complex 1 (TSC1) and tuberous sclerosis complex 2 (TSC2) gene mutation is associated with PEComa, which causes hyperactivation of the mammalian target of rapamycin (mTOR) signaling pathway. The gene discussed is TSC2; the disease is neoplasm with perivascular epithelioid cell differentiation.