The aim of the study was to evaluated the prognostic significance of TIL subtypes (CD4+, CD8+, FOXP3+ T cells) and their location (stromal "s" and intratumoral "i" CD4+ and CD8+) in BC patients, focusing on the association between these markers and immunocheckpoint molecules such as cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death ligand 1 (PD-L1) and its receptor (PD-1).
We performed immunohistochemistry for CD8 (cytotoxic T cells (CTL)), FOXP3 (regulatory T cells (Tregs)), and GATA3 (Th2 cells) in 106 formalin-fixed paraffin-embedded invasive breast cancer tissue samples and analyzed both the numbers and percentages of investigated cells in tumor-associated infiltrates.