As shown in Figure 1, we found high MDR-1 mRNA levels in the YAPC cell line characterized by the presence of homozygous polymorphisms in exons 21 and 26 (2677T>G and 3435T>C, respectively) and very low levels in the other PDAC cell lines, in particular BxPC-3 and MIA PaCa-2, bearing no variation or heterozygous status for the selected variants, compared to the non-tumor cell line. Here, ABCB1 is linked to neoplasm.