PDCD1 and esophageal squamous cell carcinoma: Preclinical studies have confirmed that programmed cell death 1 (PD-1) inhibitors combined with chemotherapy can further enhance the host’s immune response and inhibit cancer cell immune escape.15 Neoadjuvant treatments combining PD-1 inhibitors with chemotherapy have been shown to induce tumor regression and achieve major pathological response in 83% of patients with lung cancer in the NADIM study.16 However, to date, there has been no conclusive evidence to support the effectiveness of neoadjuvant immunotherapy in patients with ESCC.