RAB22A and osteosarcoma: Most importantly, the exosomes from cells stably expressing the 141-142AA mutant of Rab22a-NeoF1 lacked the enhancement of cell migration and invasion in both U2OS and 143B cells (Fig. 3e), as well as the lung metastases of 143B-Luc cells in the orthotopic osteosarcoma metastasis model in vivo (Fig. 3f–h and Supplementary Fig. 3g).