GFRA1 and colorectal carcinoma: To test whether GFRA1 hypomethylation will promotes CRC metastasis, HCT116 cells after transfection with dcas9-TET1CD-gGFRA1-5 or dcas9-TET1CD-gGFRA1-6 were injected into the tail vein of BALB/c nude mice.