Based on research related to Hb and RDW in malignant tumors, Sun et al. 24 was the first to report the prognostic value of the baseline Hb‐to‐RDW ratio (HRR) in esophageal squamous cell carcinoma (ESCC) in 2016. The gene discussed is GSTM1; the disease is esophageal squamous cell carcinoma.