Results from 5 studies analyzing a total of 319 bladder cancer patients with multiple tumors and 281 bladder cancer patients with single tumors demonstrated that methylated CDH13 was significantly associated with patients harboring multiple tumors (OR = 1.45, 95 % CI = 1.03–2.04, P = 0.032) (Fig. 6). Here, CDH13 is linked to urinary bladder carcinoma.