ABCG2 and colorectal carcinoma: Our findings are in agreement with previous findings in a study of ABCC2 and ABCG2 mRNA levels in normal and affected colonic tissue from 51 CRC patients [44], where ABCC2 mRNA level was higher in tumour tissue compared to unaffected tissue from the same individual, and the ABCG2 mRNA levels were found to be lower [44].