S100A1 and neoplasm: Functional and mechanistic investigations have characterized the role of tumor-intrinsic S100A1 ablation in promoting M1-like macrophage polarization via the S100A1/ubiquitin-specific protease 7 (USP7)/p65/GM-CSF regulatory axis, thus enhancing T-cell-mediated antitumor immunity and potentiating immunotherapy efficacy.