In the context with these data, here we have identified that YKL-40 expression is negatively associated with GATA3, E-cadherin, ER, and PR; therefore, we demonstrate that YKL-40 together with other markers including Her2/neu, ER, PR, GATA3, and E-cadherin could serve as a powerful tool for the diagnosis and prognosis of breast cancer as well as a potential target for future cancer therapy. Here, PGR is linked to breast cancer.