CHEK2 and liver cancer: We have also demonstrated that cyproheptadine interferes with cell cycle progression via the activation of p38 MAPK activity in HepG2 cells and the activation of both p38 MAPK and CHK2 activities in Huh-7 cells, which subsequently mediate, through G1/S cell cycle regulatory proteins, the induction of apoptotic or non-apoptotic cell death in these liver cancer cells.