HMOX1 and colonic neoplasm: The work by Wu et al. reported the occurrence of Casp-3 and PARP-dependent activation of apoptosis following induction of HO-1, demonstrating a correlation between HO-1 activity and colon cancer proliferation through a suggested increase of ER stress especially in those cell lines less differentiated as COLO205, HCT-15 and LOVO [34].