TERC and osteosarcoma: However, although some ALT cell lines show no TERC expression, i.e., U2OS, KPD, NY (osteosarcoma cell lines) and immortalized fibroblasts (WI38-VA13, SUSM-1, KMST6, MDAH087), other ones show normal (AG11395 fibroblasts) or even high (SaOS-2 osteosarcoma, SK-LU-1 lung carcinoma, GM847 fibroblasts) levels of TERC.