We found that, in contrast to the increased p38 MAPK phosphorylation and expression of cell cycle–regulating proteins upon cyproheptadine treatment, co-treatment with SB202190 and cyproheptadine significantly inhibited p38 MAPK phosphorylation in both HCC cell lines, decreased HBP1 and p16INK4A expression in HepG2 cells, and decreased p27 expression in Huh-7 cells (Additional file 1: Figure S3). This evidence concerns the gene CDKN2A and hepatocellular carcinoma.