TP73 and cancer: In this study, we isolated two liver stem cell lines (HepCY & HepCO) from normal young (CY) and old human (CO) liver tissues and determined TP73 expression in normal human liver stem cells, hepatocellular carcinoma (HCC) cell lines (HepG2, SNU398, SNU449 & SNU475), gastrointestinal (GI) cancer cell lines (Caco2 & HCT116) and normal skin fibroblasts cell line (HS27) to demonstrate the correlation of TP73 expression in tumorigenesis.