Although it has been reported that intratumoral injection of Fn can enhance the therapeutic effect of ICB by increasing CD8+ tumor-infiltrating lymphocytes (TILs) in tumors, considering that Fn is usually considered a carcinogenic bacterium (which also suggests its proinflammatory ability), we further considered using Fn-OMV to observe whether similar effects could be obtained. Here, FN1 is linked to neoplasm.