CARM1 serves as a coactivator of transcription for estrogen alpha and androgen receptors in breast and prostate cancers.[21, 22] It can also directly methylate PKM2 and activate aerobic glycolysis, thereby promoting breast cancer development.[23] Moreover, targeting CARM1 can sensitize resistant tumors to immunotherapy and enhance antitumor T‐cell function.[24] However, the role of CARM1 in ferroptosis remains unclear. Here, PKM is linked to breast carcinoma.