Cause-specific survival according to the four tumour microenvironment types based on PD-L1 and TILs. Kaplan–Meier curves for each type: type I (PD-L1+/TILs+) adaptive immune resistance, type II (PD-L1−/TILs−) immunological ignorance, type III (PD-L1+/TILs−) intrinsic induction, and type IV (PD-L1−/TILs+) tolerance. At the bottom, the table shows the log-rank test between groups. PD-L1 programmed death ligand 1, TILs tumour infiltrating lymphocyte.