MCL1 and chronic myelogenous leukemia, BCR-ABL1 positive: In the context of CML, studies have shown that HHT/ssHHT most likely act by inhibiting protein synthesis, and also by increasing apoptosis, in part by increasing turnover of myeloid cell leukemia 1 (MCL-1), an anti-apoptotic protein of the Bcl-2 family [29, 30].