With an in vitro IC50 of 27 nM [126, 127], TP-0903 disrupts AXL phosphorylation, reverses EMT, and increases the depletion of anti-apoptotic proteins MCL-1, X-linked inhibitor of apoptosis protein (XIAP), and BCL-2, fostering dose-dependent apoptosis of primary chronic lymphocytic leukemia (CLL) B-cells, even in cases with adverse prognostic factors like 17p/p53 deletions or prior exposure to agents like ibrutinib [128, 129]. This evidence concerns the gene MCL1 and B-cell chronic lymphocytic leukemia.