Moreover, a recent study in a sarcoma mouse model revealed that presentation of peptides by tumor cells on class II major histocompatibility complex (MHC) and their recognition by CD4+ Th1 cells was crucial to generate functional CD8+ T cell responses during ICB with anti-PD-1, anti-CTLA-4, or combination of both (41). Here, CTLA4 is linked to neoplasm.