For prostate cancer diagnosis, chitotriosidase presented a significant AUC of 0.64 (p < 0.05) at the cut-off value of 13.80 nmol/mL/h, and also neopterin had a significant (p < 0.0001) AUC of 0.76, at the cut-off value of 7.6 nmol/L. The gene discussed is CHIT1; the disease is prostate cancer.