Recent studies showed that inhibition of heat shock protein 90 (Hsp90) decreased the number of leukemia stem cells, caused BCR-ABL protein degradation by the ubiquitin-proteasome pathway, and prolonged survival of mice with CML induced by BCR-ABL-T315I [189, 190]. Here, ABL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.