We have now demonstrated that protein expression of human estrogen receptor alpha 36 (ERα36), an alternative splicing variant of human estrogen receptor alpha 66 (ERα66), is highly increased in TKI-insensitive CD34+ chronic myeloid leukemia (CML) cells and BCR-ABL-T315I mutant cells, and is abnormally localized in plasma membrane and cytoplasm. The gene discussed is CD34; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.