There is a potential link between immune response and HLA-DR4 (encoding the major histocompatibility complex, class II, DR beta 4), HLA-DR3, TNFα (encoding tumor necrosis factor-alpha), and other genes in the oral cavity, and dental caries: a positive HLA-DR4 allele might increase the risk of early childhood caries (Opal et al., 2015). The gene discussed is TNF; the disease is dental caries.