Min et al. used myeloid-specific HO-1 gene knockout (mHO-1-KO) and transgenic (mHO-1-Tg) mice to delete or overexpress HO-1, verifying that myeloid HO-1 expression improves liver IR damage by promoting macrophage M2 phenotypic polarization. Here, HMOX1 is linked to digestive system neoplasm.