Molecular biology of chronic myeloid leukemia

Detailed information on the crystal structure of the pharmacologically targeted domains of the BCR ‐ ABL molecule and on its intracellular signaling, which are potentially involved in growth, anti‐apoptosis, metabolism and stemness, has made the study of chronic myeloid leukemia the most successful field in tumor biology. However, we now face the issue of drug resistance due to deregulation in the quality control of both DNA and protein. BCR ‐ ABL is basically a misfolded protein with intrinsically disordered regions, which not only produces endoplasmic reticulum stress followed by unfolded protein response in some settings, but also conformational plasticity that may affect the structure of the whole molecule. The intercellular signaling derived from the leukemic cell microenvironment may influence the intracellular responses that take place in a manner both dependent on and independent of BCR ‐ ABL tyrosine kinase activity.