Notably, honokiol triggers ferroptosis in AML cells by increasing the expression levels of HMOX1, and furthermore, zinc protoporphyrin, an HMOX1 inhibitor, prevented the honokiol-induced ferroptosis of several AML cell lines (THP-1, U-937 and SKM-1 cells) (86). Here, HMOX1 is linked to acute myeloid leukemia.