Total of 20 genes among the hub genes were significantly correlated with OS and DFS (Supplementary Table S6), of which the six key genes screened by univariate Cox analysis, which were significant risk factors for OS in BLCA, were CNTN1, DACT3, MYLK1, PDE2A, RBM24, and ST6GALNAC3 (p < 0.01) (Table 3 and Supplementary Fig. S2). This evidence concerns the gene PDE2A and bladder transitional cell carcinoma.