In an osteosarcoma in vitro and in vivo models, ATRA inhibited osteosarcoma metastasis via inhibiting M2 polarization of TAMs independent of STAT3/6 or C/EBPβ signaling, thus proposing ATRA as an anti-metastatic potential treatment in osteosarcoma patients (Zhou et al., 2017). This evidence concerns the gene STAT3 and osteosarcoma.