CK7+/CK20-: breast, lung, ovarian cancer CK7-/CK20+: colorectal and Merkel cell carcinomas CK7+/CK20+: upper GI-tract cancers, some pancreatic cancers CK7-/CK20-: prostate, hepatocellular carcinomas. The gene discussed is KRT7; the disease is ovarian carcinoma.