The rationale of testing the reversal effect of VKNG-1 on these cell lines is because the ABCC subfamily (includes ABCC1 and ABCC10 transporters), commonly called the multidrug resistance protein (MRP) family, has been shown to be associated with MDR in various cancers, including lung cancer (both small and non-small cell lung cancers), bladder cancer and breast cancer [32]. Here, ABCC1 is linked to cancer.