IGF1 and esophageal adenocarcinoma: McElholm et al. analyzed 102 SNPs in the IGF axis [17] and characterized three genetic variants that appeared to be associated with esophageal adenocarcinoma: rs6214 in the IGF-I gene, rs6898743 in the GHR gene and a CA-repeat in the promoter region (5′-UTR) of the IGF-I gene, the latter variant however being very rare.