ALLC and breast cancer: In addition, peripheral lymphocytes and neutrophils can migrate toward a tumour site and infiltrate the tumour microenvironment.18–21 Thus, research on immunologic markers in peripheral blood, such as NLR, platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio is being actively conducted.22,23 However, there is a lack of data on ALC as a prognostic marker in breast cancer.