Sabatolimab (an anti-TIM-3 monoclonal antibody) in combination with HMAs had durable responses in HR-MDS and AML patients.607 In a phase 1b trial, ipilimumab (CTLA-4) showed limited efficacy in HR-MDS patients after failing from HMAs.610 HMAs could increase the expression level of PD-1, PD-L1, PD-L2, and CTLA-4 in patients with AML and MDS, which caused HMA resistance.610 Therefore, there are clinical trials combining PD-1/PD-L1 inhibitors with HMAs in AML and MDS patients. Here, PDCD1 is linked to acute myeloid leukemia.