To determine whether forced expression of BMAL1 in BMAL1-deficient, HNF4α-positive hepatoblastoma and HCC impairs tumor growth, AML12, HepG2, Huh7, and SNU449 cells were transfected with an expression vector for BMAL1 and analyzed for growth and viability. This evidence concerns the gene HNF4A and hepatocellular carcinoma.