CD34 and chronic myelogenous leukemia, BCR-ABL1 positive: More interestingly, increased expression of surface ERα36 was found in CD34+ IM-nonresponder cells compared to IM-responder cells or CD34+ normal BM cells, and knockdown of ERα36 in CML cells increased the sensitivity to IM treatment, while suppression of full length ERα66 did not have an inhibitory effect.