T315I mutation
(… myoo-TAY-shun)
A type of mutation (change) in the BCR::ABL1 fusion protein, which is an abnormal protein found in most people with chronic myelogenous leukemia and in some with acute lymphoblastic leukemia. The T315I mutation may make cancer cells resistant (unable to respond) to anticancer drugs called tyrosine kinase inhibitors. Checking for the T315I mutation in cancer cells may help plan cancer treatment.