CHI3L1 and invasive lobular breast carcinoma: In the YKL-40-positive tumor compared with the YKL-40 negative subgroup of cancer patients, significantly higher mean serum YKL-40 levels were observed in patients with invasive lobular carcinoma (P<0.0167), TNM stage II or III (P<0.001), positive lymph node metastasis (P = 0.008), or who were deceased (P = 0.034).