CD274 and myelodysplastic syndrome: Since current trials have reported limited efficacy of PD-1/PD-L1 blocker in MDS/AML, numerous ongoing efforts are being made for assessing the effectiveness of novel combinations, including with novel HMAs, other immune checkpoint inhibitors (ICIs), histone deacetylase inhibitors (HDACi), tumor vaccines or chemotherapeutic agents (Table 3).