CD44 and carcinoma: Many CD44 variant isoforms have tissue-specific expression; CD44v8-10 is expressed in epithelial tissues and in epithelial-type carcinomas of the pancreas, prostate, breast, and lung [7], where it has been extensively studied as a specific marker of malignant cells, with increased expression observed during gastric carcinogenesis in a murine model and in the adenoma to carcinoma progression in human colorectal cancer [8–10] and gastric cancers [11].