CEACAM5 and breast cancer: Breast cancer is characterized by highly heterogeneous.[11] Currently, there is a persistent rise in reported cases of BC among young women, with low 5-year survival rates, which have been associated with delayed diagnosis and higher local recurrence rates.[12] In the early-stages of BC, commonly utilized markers like CEA and CA15-3 demonstrate relatively limited sensitivity and specificity.[13] Therefore, in order to facilitate early diagnosis of breast cancer, it is crucial to investigate novel serum markers.