We reasoned that it is important to characterize glycosylation structures of IgG in prostate diseases, which have been relatively little understood in contrast to those previously clarified with other APPs, including α1‐acid glycoprotein, haptoglobin, and antichymotrypsin sampled from patients with various cancers including prostate cancer 6, 15, 16, 17, 18, 19, 20, 28, 29. Here, HP is linked to prostate carcinoma.