Among the five most differentially expressed proteins—A1BG, APOH, CFH, VTN, and SERPINA1—we prioritized candidates with a base expression level greater than 0.5 and prior tumor‐related associations reported in the literature.[20] Functional assays revealed that conditioned media from A1BG‐depleted adipocytes significantly reduced osteosarcoma cell viability following cisplatin treatment (Figure 3G; Figure S10A–E, Supporting Information), indicating that A1BG is a key driver of adipocyte‐mediated chemoresistance. Here, SERPINA1 is linked to osteosarcoma.