For the diagnosis of breast cancer, the AUC (area under the curve) was 0.97, indicating significance (p < 0.0001) for chitotriosidase at the cut-off value of 13.80 nmol/mL/h, though not for neopterin (AUC = 0.68, p = 0.88). Here, CHIT1 is linked to breast carcinoma.