PDCD1 and neoplasm: Further research uncovered proximity-dependent (<250 μm) chemokine ligand 13-positive (CXCL13+) T cell–lysosomal-associated membrane protein 3-positive (LAMP3+) dendritic cell (DC) interactions via PD-1/PD-L1, a signaling axis utilized by DC to attenuate T cell activation (Peng et al., 2020), occurring at the tumor-stroma boundaries in dMMR and anti-PD1-responding (partial response (PR)/complete response (CR)) tumors, highlighting distance-critical signaling (Table 2).