To confirm the presence of EGFR ligands also in vivo, we collected blood samples from 13 newly diagnosed CML patients and extracted RNAs; the real‐time PCR showed that CML patients expressed mRNA of HBEGF, EREG and AREG (Fig. 1B and Fig. S2A and B). Here, EREG is linked to chronic myelogenous leukemia, BCR-ABL1 positive.