However, studies have explored the role of HLA-G in other diseases like gastric cancer, which illustrates the association between HLA-G expression and disease severity.17 Other studies indicated that sHLA-G can be a potential diagnostic biomarker for head and neck cancer due to its suppressive function of this molecule and over-expression in diseased patients with the influence of cytokines.18 Further studies are needed to compare these results with the current study and to elucidate the specific role of sHLA-G in GERD pathogenesis. This evidence concerns the gene HLA-G and head and neck cancer.