Recent studies have demonstrated that the infiltration of Fn into tumors reduces cytotoxic CD8+ T cell infiltration, inhibits T cell cytotoxic function, and contributes to the formation of an immunosuppressive tumor microenvironment.[26, 27, 28] To investigate the effect of NM@PLGA‐MTI‐OXA on modulating the immune microenvironment, immunohistochemical staining for CD3, CD4, and CD8 proteins was performed on tumor sections from the AD/Fn and Fn‐infected liver metastasis models, as well as the MC38/Fn colon axillary tumor model. Here, FN1 is linked to neoplasm.