SOCS5 and osteosarcoma: As an example of promoting tumor metastasis, COL6A1 (commonly over-expressed in osteosarcoma) could be up-regulated by enhanced enrichment of H3K27 acetylation at the promoter region, which increases osteosarcoma lung metastasis via interacting with SOCS5 towards suppressed STAT1 expression and converting normal fibroblasts to cancer-associated fibroblasts (CAFs) [18].