CTLA4 and neoplasm: In addition, by IHC staining, we observed that the expression of several immune checkpoint or co-stimulatory molecules (OX40, CTLA-4, LAG3, TIM-3, immune cell PD-L1, PD-1) was significantly higher in IS-A subgroup (Figure 5 and Figure S9), whereas we found no association between the PD-L1 (tumor cell) level and immune type.