In recent years, literature reviews of patients with various types of cancer (breast, colorectal, ovarian, kidney, prostate, small-cell lung, melanoma, and glioma) suggest that the serum YKL-40 level detected with the enzyme-linked immunosorbent assay (ELISA) could be a promising predictor of tumour burden and an independent prognostic variable of a short relapse-free interval as well as short overall survival [3-12]. The gene discussed is CHI3L1; the disease is cancer.