Immunological mechanisms emerge as pivotal, with viral infections potentially triggering dysregulated immune responses in susceptible individuals harboring specific immunogenetic variations (for example, HLA-DRB1*14:54, DQB1*05:03, and the conserved haplotype DRB1*14:54-DQB1*05:03 in Mexicans confer risk for the development of achalasia) [65]. This evidence concerns the gene HLA-DRB1 and viral infectious disease.