IGFL2 and nonpapillary renal cell carcinoma: The contribution of IGFL2-AS1 to ccRCC progression was also validated by delivering in vivo siRNAs into pazopanib resistant OSRC-2 tumors (n = 7 for vehicle treated group, n = 8 for siRNAs treated group), which revealed that siRNAs targeting IGFL2-AS1 remarkably slowed down tumor growth as well as decreased VM number (Fig. 7D–F), strengthening the role of IGFL2-AS1 in ccRCC progression via altering its VM development.