BIRC5 and renal cell carcinoma: Through subgroup analysis, the results showed that survivin expression still had association with Asian patients (n=5, HR=2.57, 95%CI: 1.63-4.07, p<0.001), in RCC (n=2, HR=2.15, 95%CI: 1.11-4.16, p=0.023) and in ccRCC (n=2, HR=3.04, 95%CI: 1.61-5.76, p=0.001).