Increased expressions of cellular ATP-binding cassette transporters may be a promising diagnostic marker for colorectal cancer

Expression levels of mRNA for ABC transporters. The expression levels of each ABC transporter were determined using qPCR technique. Their expressions were normalized to the expression of GAPDH housekeeping gene using REST 2009 software. Then, the normalized results were compared using an unpaired t-test with Welch’s correction to calculate the degree of differences in expression between two independent groups. Regarding the mRNA expression levels of ABCB1, ABCC1, and ABCG2 transporters in the blood of CRC patients, the results showed a significant difference in the expression levels of the three ABC transporters (these were higher in CRC patients compared with healthy controls). P values were as follows: *p<0.05; ***p<0.0001.