IGF1 and renal cell carcinoma: In the test set, we found that the IGF1 rs5742714 and rs6214 polymorphisms were significantly associated with a decreased risk of RCC (OR = 0.66, 95% CI = 0.48–0.92 and OR = 0.65, 95% CI = 0.45–0.86 for rs5742714 and rs6214, respectively).