Accumulating evidence from case series, retrospective analyses, and a pivotal trial demonstrates notable response rates (~40% or higher) and prolonged PFS in patients with advanced or unresectable PEComas treated with agents such as sirolimus, everolimus, or nab-sirolimus.45,46 These agents show activity even in bulky retroperitoneal or abdominopelvic tumors, sometimes enabling surgical resection when used neoadjuvantly.46,47 Given the rarity of PEComa, formal trials are limited, but all available data consistently support mTOR blockade as an effective therapy. The gene discussed is MTOR; the disease is neoplasm with perivascular epithelioid cell differentiation.