CCND1 and esophageal cancer: Recent studies have found that several genes and molecules are involved in the origin and/or progression of esophageal cancer, including TP53 [1], deleted in esophageal cancer 1 (DEC1) [2], deleted in colorectal cancer (DCC) [3], deleted in lung cancer 1 (DLC1) [4], cyclinD1 [5], and adenomatous polyposis coli (APC) [6].