GSTM1 and head and neck cancer: Although a large number of studies have reported the separate effects of Hb and RDW on the prognostic value of gastric cancer, studies have confirmed the predictive power of Hb/RDW in lung cancer, esophageal cancer, and head and neck cancer [5, 12], but Hb/RDW research on the prognostic impact of gastric cancer patients is still limited.