PDCD1 and neoplasm: Especially in TNBC, increased tumor-infiltrating lymphocytes (TILs) are not only associated with favorable outcomes but also have the potential to serve as an indicator of a better response to chemotherapy, neoadjuvant chemotherapy, as well as anti-programmed cell death 1 (PD-1) or anti-programmed cell death 1 ligand 1 (PD-L1) immunotherapy (12–17).