Tumorigenicity of HCC21 cells in immunocompromised mice. (A) Nude mice and NOD/SCID mice injected subcutaneously with 2x106 and 1x106 HCC21 cells, respectively, after 12 weeks. The middle panel shows the subcutaneous tumors derived from HCC21 cells 12 weeks after injection (scale bar = 10 mm). The lower panel shows the tumorgenicity of HCC21 cells. (B) Protein expression of HBV core antigen and AFP in patient’s tumor specimen, HCC21 xenograft tumors in NOD/SCID and nude mice, and cultured HCC21 cells at passage 12.