Tumor-derived exosomal HMGB1 promotes esophageal squamous cell carcinoma progression through inducing PD1+ TAM expansion

a Gating strategy for flow cytometry to enumerate macrophages infiltrating ESCC. Debris and doublets were excluded, followed by quantification of TAMs as CD45+？Hoechst？ F4/80+？CD11b+. b PD1 level estimation in TAMs from ESCC tissues. Representative graphs of PD1 levels in TAMs are shown. c Associations of PD1+ TAMs with ESCC patients’ TNM stage are shown. d Immunofluorescence analysis of PD1 (green) and CD68 (red) expression levels in ESCC tissue. e Association of tumor PD1+ TAMs with patient survival. *p？<？0.01, **p？<？0.001 (Student’s t-test