CCL21 and neoplasm: To elucidate cellular communication within the PLXDC1+ TPSC‐associated niche, we analyzed cell‐cell interaction using NicheNet.[34] Top‐ranking ligand‐receptor pairs were identified, covering ECM interactions (e.g., MMP9‐CD44, COL1A1‐ITGB1, and ITGB1/ITGA4‐JAMs), cytokine interactions (e.g., CXCL12‐CXCR4, CCL21‐CCR7, and VEGFA‐NRPs), and interactions known to facilitate tumor cell proliferation and migration (e.g., CDH1‐CDHRs, EFNA/Bs‐EPHA/Bs, and TGFB1‐TGFBRs) (Figure 6A).