Purpose: Breast cancer (BC) is the most common cancer and the second leading cause of cancer death among women. While receptor-targeted therapies are used for other subtypes due to the presence of such receptors, studies are still continuing on receptor expression in order to identify new therapeutic targets as the triple-negative breast cancer (TNBC) lacks a target receptor and its prognosis is worse than the other subtypes. Cyclin D1 (CycD1) is a cell cycle regulator protein. It is stated that its overexpression plays a role in carcinogenesis. With the present study, we aimed to evaluate the prognostic significance of immunohistochemical expression of CycD1 in patients with TNBC
