The present study applied patch-clamp fast whole cell recording, fura-2 Ca2+ imaging, immunoblotting, flow cytometry, immunofluorescence microscopy, and colony formation assay to analyse radiogenic hERG1 activation, hERG1-dependent Ca2+ signaling and activation of Ca2+ effector proteins, bromodeoxyuridine (BrdU) incorporation and cell cycle progression, repair of DNA double-strand breaks, as well as cell death and clonogenic survival in irradiated CML cells. Here, KCNH2 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.