FOXP3 and oropharynx cancer: Reasons for exclusion included irrelevant manuscripts which did not tackle the role of Tregs in oral and oropharyngeal cancer (n = 478), manuscripts that focused on tumors other than oral or oropharyngeal; laryngeal/esophageal (n = 82), salivary gland (n = 44), thyroid gland (n = 32) or gastric tumors (n = 18), review articles (n = 13), one study looked at the role of Tregs in periodontal disease and two articles were excluded because they assessed the expression of Foxp3 in tumor cells rather than assessing Tregs.