The observations made here with nilotinib-vincristine combinations in leukemia cells are in line with previously reported synergistic in vitro effects of nilotinib and vincristine in certain ABCB1- or ABCC10-overexpressing tumors (81–83), and with the absence of antagonism in several other preclinical tumor models, including oral squamous cell carcinoma (84, 85). Here, ABCB1 is linked to oral cavity squamous cell carcinoma.