STAT3 and nonpapillary renal cell carcinoma: A new study found that ccRCC-derived exosomes can activate the miR34/miR449-STAT3 signaling pathway by delivering lncARSR, which in turn promotes the transformation of M1 macrophages to M2 and enhances the phagocytic ability of macrophages, which in turn induces angiogenesis and ultimately promotes the development and progression of tumors (32).