IGFLR1 and nonpapillary renal cell carcinoma: Although studies have shown that high expression level of IGFLR1 could predict poor survival among patients with ccRCC (Parker et al., 2002; Sichani et al., 2010; Lkhagvadorj et al., 2014), the mechanism of the cancer-promoting effect of IGFLR1 has been still unclear, and previous studies were limited to carbohydrate metabolism (Solarek et al., 2015).