Results above indicate Bcr-abl impairs Calpain activity in Lin−CD34+ myeloid progenitors (functional LSCs) through increased Gas2 expression, and in G-CSF-differentiated cells (differentiating progenitors and CML granulocytes) through increased Calpastatin. This evidence concerns the gene GAS2 and chronic myelogenous leukemia, BCR-ABL1 positive.