VEGFA and nonpapillary renal cell carcinoma: Though various signaling crosstalk pathways involved in carcinogenesis have been proposed as underlying treatment targets consisting of mammalian target of rapamycin (mTOR), vascular endothelial growth factor (VEGF) or mitogen-activated protein kinase (MAPK), drug resistance and limited progression-free survival (PFS) still exist, especially for metastatic ccRCC [5–7].