ABCC1 and lung cancer: In contrast, TMP195 had no significant effect on ABCC1-mediated resistance to etoposide, a known drug substrate of ABCC1, in either COR-L23/R, an ABCC1-overexpressing MDR variant of COR-L23/P human lung cancer cells (Figure 1E) or in HEK293 cells transfected with human ABCC1 (MRP1, Figure 1F and Table 1).