Multiple studies have found a significant correlation between a short tandem repeat (STR) polymorphism (TCA3/TCA3) in the 3′-untranslated region (UTR) of ECRG2 and increased incidence as well as poor prognosis of esophageal [8,57,58,59] and oral [60] cancers in various patient populations. This evidence concerns the gene SPINK7 and cancer.