genetically engineered macrophage to express a non‐secreted form of EGFP‐TNF‐α fusion protein and encapsulated a NIR‐responsive heat‐nanogenerators (HIMs) into macrophages.[235] Due to the intrinsic tumor tropism of macrophages and NIR‐responsive capability of HIMs, the resultant HIMs@eMET could actively target tumor site and spatiotemporally control the release of non‐secreted TNF‐α, leading to selective and remarkable toxicity to tumors. Here, TNF is linked to neoplasm.