CASC2 and neoplasm: CASC2 is a well-known tumor suppressor.7 CASC2 expression was down-regulated in osteosarcoma tissue samples and cell lines and overexpression of CASC2 inhibited osteosarcoma cell proliferation, colony formation, and invasion ability.20 Zeng et al. suggested that the expression of CASC2 was reduced in the hepatocellular carcinoma (HCC) tissues and cell lines.