Serum immunoglobulin (Ig) levels in UC (UC of the bladder (UCB) and upper urinary tract UC (UTUC)) patients and healthy volunteers (HVs) and prostate cancer (PC). (a) Serum total Igs (sum of IgG1-4, IgM and IgA) levels in the UC, HV and PC groups; (b) Serum total IgG (IgG1-4) levels in the UC, HV and PC groups; (c) Serum IgM levels in the UC, HV and PC groups; (d) Serum IgA levels in the UC, HV and PC groups. The results shown are representative of three independent experiments. Intergroup differences were statistically compared using the Mann–Whitney U-test for non-normally distributed models.