BMP6 and hepatocellular carcinoma: In cell proliferation and colony formation assays, the overexpression of BMP-6 had a clear impact on in vitro HCC cell colony formation in Hep-1 (Figure 6B) and SMMC-7721 cells (Figure 6C); however, overexpression of BMP-6 showed no clear impact on in vitro HCC cell proliferation using the CCK-8 assay in Hep-1 (Figure 6E) and SMMC-7721 cells (Figure 6D).