CD68 and primary central nervous system lymphoma: M1-like macrophages (CD68+CD163low) play an antitumoral role, whereas M2-like macrophages (CD68+CD163high) usually have protumoral effects, are predominantly found within the tumor, and express immune-checkpoint-related molecules such as PD-L1 and TIM3, conferring an immunosuppressive TME to PCNSL [50].