COLCA1 and colorectal neoplasm: The cis-eQTL analysis with the proxy SNP demonstrated similar expression patterns in the colorectal tumor tissue samples, where the risk allele associated with lower expression levels compared to the reference allele for the COLCA2 (p = 8.90 × 10−4) and COLCA1 (p = 4.70 × 10−3) genes (Additional file 4: Figure S2).