PDCD1 and breast cancer: Another study of 177 patients treated with NACT without targeted anti-PD1 therapy, 38.4% of which were ER+ BC, also reported no association between PD-L2 and clinical outcome; however, in that study, ER+ patients were grouped with HER2+ for response assessment in “non-TNBC” versus TNBC, which might have impacted the data interpretation [8].