ABCB1 and cancer: Drug-sensitive parental KB-3-1 and ABCB1-overexpressing KB-V-1 cancer cells were treated with 0.5 μM of colchicine, a known transported substrate of ABCB1 [30] and a known inducer of apoptosis [40], in the presence or absence of 5 μM of erdafitinib for 48 h before processed as detailed in the Materials and Methods.