In addition, many immunoglobulin genes such as IGHG3, IGHG4, IGHG1, IGHM, IGLC2, IGLC1 and IGKC were up-regulated in HBV+ ESCC patients and down-regulated in HBV–#1 after anti-PD-1 therapy (Supplementary Fig. S5, Supplementary Table 8). Here, PDCD1 is linked to esophageal squamous cell carcinoma.