CD86 and neoplasm: Compared with PBS and PEG(0) NP, PEGylated NPs as well as the soluble vaccine group upregulated CD86 and downregulated CD206 on macrophages in TDLNs (Figure 5I,J), resulting in a decreased ratio of M2/M1‐like macrophages (Figure 5K).[18] We observed similar activation of DCs and macrophages in tumor‐draining axillary LNs, but not in contralateral non‐tumor‐draining inguinal or axillary LNs (Figures S8 and S9, Supporting Information).