CD4 and esophageal cancer: Further flow cytometry analysis, as shown in Fig. 2d and Supplementary Fig. 6a–c, confirmed that lnc-EGFR expression in the CD4+ T cells was accompanied by an increased ratio of Treg cells within the tumour microenvironment of either HCC or other human malignant tumours (oesophagus cancer, gastric cancer, lung cancer and colon cancer); CD4+-T-cell-specific EGFR also correlated positively with Foxp3, but correlated negatively with interferon γ (IFN-γ), depending on the expression of lnc-EGFR (Fig. 2e,f and Supplementary Fig. 6d,e).