<prompt> ck 7 negative and ck 20 negative tumor is?Prostate carcinomaCarcinoma colonUrothelial carcinomaMesothelioma  <response>: Ans is a i.e. Prostate carcinoma o Cytokeratin 7 CK 7 and cytokeratin 20 CK 20 are low molecular weight cytokeratins. Their anatomic distribution is generally restricted to epithelia and their neoplasms.Cytokeratin immunohistologyTumorsoragnsCK7 CK20carcinomas of .bile duct extrahepatic gallbladder, mucinous bronchioloalveolar carcinoma of lung, pancreas carcinoma, urothelium carcinoma, primary mucinous tumors of ovary, upper GI tract and endocervix.CK7CK20-carcinomas of bile duct intrahepatic, breast, endocervical and endometrial adenocarcinoma, esophagus distal, lung not mucinous bronchioloalveolar, salivary gland, thyroid, mesotheliomaCK7- CK20carcinoma of colon particularly early stage, primary mucinous tumors of lower GI tract, GI stromal tumor Krukenberg, primary bladder adenocarcinoma.CK7-CK20-carcinoma of adrenal cortex, prostate 