PTTG1 and osteosarcoma: 5). It is expressed most abundantly in several carcinoma cell lines including cervix carcinoma HeLa cell, choriocarcinomas JEG-3 and JAR, breast adenocarcinoma MCF-7, osteogenic sarcoma U-2OS, hepatocellular carcinoma Hep 3B, lung carcinoma EY, ovarian CAOV3 and thyroid carcinoma TC-1. Saez et al. [25] also isolated and characterized hpttg from human thymus and studied the expression of hpttg in human pituitary adenomas.