We also included additional carcinoma IHC stains to rule out that the peritoneal tumors were of different origins: CK7, CK20, and villin for gastrointestinal, urothelial primary tumor, TTF-1 for lung adenocarcinoma, CD10, RCC, and vimentin for clear cell renal cell carcinoma, and P504S and PAX-2 for papillary renal cell carcinoma. The gene discussed is PAX2; the disease is lung adenocarcinoma.