In the migratory Transwell assays, chondrosarcoma cell migration was significantly enhanced by M2 macrophages stimulated by hypoxic tumor-derived exosomes compared with normoxic exosomes (Figure 4B), pretreatment with M2 macrophages cell with Arginase-1 antibody significantly inhibited chondrosarcoma cell migration (Figure 4B). Here, ARG1 is linked to chondrosarcoma.