CTLA4 and neoplasm: Although anti‐CTLA‐4 alone did not delay 4T1 tumor progression and metastasis, the combination of anti‐CTLA‐4 with PDT and/or magnetic hyperthermia showed significantly different primary tumor growth inhibition efficiencies and pulmonary metastatic suppression activities than the combined treatment without immunotherapy (Figure 4b–f and Figure S21a, Supporting Information).