IDO1 and neoplasm: Moreover, another study conducted by same group that using this MN patch for combination delivery of αPD1 with other immune checkpoint inhibitor, 1‐methyl‐DL‐tryptophan (1‐MT, an inhibitor of IDO), toward local tumor‐specific T cells modulation simultaneously.[215] In vivo antitumor study demonstrated that the resulting HA‐NP embedded MN (NP‐HA) could induce robust antitumor immunity to control tumor growth, further suggesting MN patch could be a promising platform for localized delivery of immunomodulatory agents to TME.