CD274 and neoplasm: We postulate that the reduction in MDSC in response to IPG0521m treatment is likely due to the crosstalk between Tregs and MDSCs, both of which have been shown to collaborate with each other in promoting tumor-immune evasion [35–37], and both of which are able to induce generation and enhance the suppressive activity of the other via various signaling pathways, including PD-L1 signaling [38, 39].