The overexpression or hyperactivation of TGF-β can be detected in a high proportion of EC patients [35, 36], and more importantly, blockade of TGF-β enhances the efficiency of PD-L1/PD-1 inhibition, inducing MAGE-A3+ specific CD8+ T-cell response in ESCC [11]. Here, PDCD1 is linked to esophageal squamous cell carcinoma.