FOXP3 and hypopharyngeal carcinoma: FoxP3+ Tregs were not significantly associated with DFS in renal (OR 3.17, 95% CI 0.13 to 9.96, P = 0.12), head and neck (OR 1.07, 95% CI 0.38 to 3.03, P = 0.89), breast cancers (OR 0.78, 95% CI 0.45 to 1.35, P = 0.38), and oro- and hypopharyngeal carcinoma (OR 0.54, 95% CI 0.15 to 1.94, P = 0.34).