A recent cohort study conducted in a mixed population (725 subjects) showed a significant association between the Cdx2 (rs11568820-AA) genotype and the susceptibility to upper respiratory tract infection (p = 0.001; OR = 1.31; 95% CI = 1.12–1.53; AA vs. GG) [55]. The gene discussed is CDX2; the disease is Recurrent upper respiratory tract infections.