ABCC4 and colorectal carcinoma: In fact, Holla and colleagues [16] reported that PGT and MRP4 mRNA levels are inversely regulated in human CRC, with PGT expression being downregulated and MRP4 overexpressed in CRC tissues and cell lines leading to higher levels of PGE2 extracellularly thus upregulating the effects of COX-2/PGE2 pathway.