MMP12 and osteosarcoma: In addition, the clinical use of available all-trans-retinoic acid (ATRA) abrogates the pro-tumorigenic phenotype of TAMs in prostate cancer by suppressing the activation of NF-κB p50 60 and reduces osteosarcoma metastasis by downregulating MMP12 (matrix metalloproteinase 12) secretion from M2-type TAMs 61.