HER2 IHC 3+ BC showed a predominantly low LNR ≤ 0.20 (P = 0.015), low post-NACT ki-67 (≤ 20%, P = 0.039), and post-NACT prognostic stage was mainly 0, IA–B or IIA (P = 0.009). Here, PSME3 is linked to breast cancer.