To further validate that TP-0903 is able to target and reduce phosphorylation of Axl in CLL B-cells from ibrutinib exposed patients, purified CLL B-cells from the ibrutinib treated cohort (n=3; Table 2) were treated with a sub-lethal dose of TP-0903 (dose determined from the TP-0903 dose-response curve) (Table 2) or left untreated for 16-20 hours. Here, AXL is linked to B-cell chronic lymphocytic leukemia.