Abstract:Objective:To explore the expression characteristics of cell keratin 19 (CK19) in different subpopulations of HepG2 cell lines of human hepatocellular carcinoma ( HCC ). Methods :Immunocytochemical staining was performed to show the expression of CK19 in SP and non-SP cells. Results:With the Hoechst 33342 extrusion assay, SP cells were found to account for 1.6% of the HepG2 cells, and CK19 was much more expressed in SP cells than in non-SP cells. Conclusions:The differential expression of CK19 can be seen in HepG2 cell lines, and most CK19 positive cells are from SP cells, indicating that HCC is heterogeneous.