To elucidate the relevant miR-451a targets in relation to radiation and colorectal cancer, we used the miRwalk algorithm to combine data from multiple target prediction databases and identified 13 genes as putative targets of miR-451a (NSMAF, OSR1, PMM2, POU3F2, SMARCA2, ARHGEF3, CAB39, ZNF644, CPD, EREG, GRSF1, MEX3C, EMSY). The gene discussed is ARHGEF3; the disease is colorectal cancer.