PEComas are related to the genetic alterations of tuberous sclerosis complex (TSC), an autosomal dominant genetic disease associated with losses of TSC1 (9q34) or TSC2 (16p13.3) genes, which seem to have a role in the regulation of the Rheb/mTOR/p70S6K pathway. The gene discussed is RPS6KB1; the disease is neoplasm with perivascular epithelioid cell differentiation.