The first report on the prognostic value in solid tumors was a study of 41 patients with recurrent breast cancer by Johansen [9], which was followed by a series of studies that evaluated the prognostic value of serum/plasma YKL-40 in solid tumors, such as gastrointestinal tumors, ovarian cancer, melanoma, lung cancer, urologic neoplasms, glioblastoma, breast cancer, squamous cell carcinoma of the head and neck and so on. Here, CHI3L1 is linked to breast carcinoma.