High COL5A1 methylation levels were correlated to a better PFI in BLCA patients (p = 0.013) but linked to a poor PFI in KIRC patients (p = 0.031), KIRP (p = 0.026), and THCA (p = 4.13e − 03) (Figure 10(c)). Here, COL5A1 is linked to bladder transitional cell carcinoma.