Flens et al. (1996) tested an impressive number of healthy tissues and tumor tissue samples by IHC using three antibodies [anti-MRP1(m5) and anti-MRP1(m6) and MRP1r1]; these antibodies were later on also employed by St-Pierre et al. (2000) and Nagashige et al. (2003) for placental MRP1 localization. This evidence concerns the gene ABCC1 and neoplasm.