In order to establish an HER2-overexpressed cell model, the protein expressions of HER2 were detected in several kinds of cancer cells, including breast (MCF-7), prostate (PC-3), gastric (AGS and MKN45), colorectal (HCT-15), lung (A549), hepatocellular (HepG2), and esophageal (Yen4) tumor cells. This evidence concerns the gene ERBB2 and neoplasm.