RAI2 and colorectal carcinoma: As shown in Figure 5E, The IC50 of 5-FU was decreased in RAI2-transfected LoVo cells (30.20 ± 6.09 μM versus 16.31 ± 2.89 μM, P=0.0234) and RAI2-transfected HCT116 cells (20.89 ± 4.23 μM versus 7.76 ± 1.66 μM, P=0.0075), while, we found no significant difference between RAI2-M-transfected CRC cells and vector control group in both LoVo and HCT116 (P>0.05).