Figure 6. Disease free survival analysis of 9 key genes in ccRCC (based on TCGA data in GEPIA). (A–I) Expression levels of PTTG1, RRM2, TOP2A, UHRF1, CEP55, BIRC5, UBE2C, FOXM1 and CDC20 are significantly related to the disease free survival of patients with ccRCC (P < 0.05).