In the recessive model, when the p21 rs3176352 GG/GC genotypes were used as the reference group, the CC homozygote genotype was associated with a 63% increased risk of ESCC (CC vs. GG/GC: adjusted OR = 1.63, 95% CI = 1.23–2.15, p = 0.0006) (Table 3). Here, CDKN1A is linked to esophageal squamous cell carcinoma.