Zhang et al. revealed that exosomal Collagen type VI alpha 1(COL6A1) derived from osteosarcoma cells promotes invasion and migration of osteosarcoma cells by secreting pro-inflammatory cytokines including IL-6 and IL-8, transforming normal fibroblasts into CAFs and mediating the TGF-β/COL6A1 signaling pathway (Zhang Y. et al., 2021). Here, TGFB1 is linked to osteosarcoma.