PDCD1 and neoplasm: In the study by Kaewkangsadan et al., it has been demonstrated that unlike intratumoral infiltration by CD4+ and CD8+ T cells, tumor-infiltrating CTLA-4+ and PD-1+ T cell levels were not associated with pathological complete response (pCR) following neoadjuvant chemotherapy (NAC) in large and locally advanced breast cancers (LLABC) [36].