MPO and neoplasm: IHC staining results (Fig. 3c) showed that I-MMAE and I-DXd potently eliminated tumor-infiltrating TANs in TME at both total TANs (Ly6G+) and pro-tumor TANs (MPO+) levels, and I-DXd reached a superior TAN elimination rate than I-MMAE, as high as 75% for total TANs and 85% for pro-tumor TANs, respectively (Fig. 3d).