MYC and breast carcinoma: For instance, HNRNPK can promote c‐myc transcription by binding to poly (C) of the c‐myc promoter both in vitro and in vivo,6, 7 and high expression of HNRNPK is usually accompanied by high levels of c‐myc in breast cancer, prostate cancer, and melanoma tissues.8, 9, 10 In contrast, HNRNPK may also act as a tumor suppressor, as haploinsufficient mice more easily form malignant tumors.11, 12, 13