To determine if GPR68 gene expression is regulated by pH, several HNSCC cell lines (Cal-27, FaDu, JHU-022, MDA-1483, UD-SCC-2, UM-SCC-47, UPCI-SCC-090) were cultured at pH 6.6, 7.0 and 7.4 for three days. This evidence concerns the gene GPR68 and head and neck squamous cell carcinoma.