SPP1 and neoplasm: Fib06 and Fib08 were enriched in tumor tissues, especially metastatic lesions (Fig. 7g; Supplementary Table S13), exhibiting proliferation quiescence (MKI67−CENPW−) and enhanced secretory capacity (e.g., CST1, CXCL14, TGM2, SPP1, IGF2) (Fig. 7d–f), corresponding to the senescence-associated secretory phenotype (SASP)48.