Single-cell RNA sequencing of sacituzumab govitecan (SG)-treated triple-negative breast cancer (TNBC) further reveals spatially distinct CD8+ T-cell clusters: DAMP-rich proximal regions harbor TCF1+ memory precursors, while distal zones are dominated by programmed cell death protein 1 high and T-cell immunoglobulin and mucin-domain containing-3 positive (PD-1hiTIM-3+) exhausted subpopulations, correlating with resistance to anti-PD-1 therapy and highlighting the need for spatial biomarkers to guide ADC–ICI sequencing [106, 107]. Here, PDCD1 is linked to triple-negative breast carcinoma.