This plasmid recruits dCas9-TET1CD to the TSS of GFRA1 via gRNA [29], thus specifically demethylating the TSS region of GFRA1. We found that most of the GFRA1 gene in CRC cell lines has high methylation modifications in the CCLE database (S4A Fig). This evidence concerns the gene GFRA1 and colorectal carcinoma.