Similarly, for the HER2-positive subtype (PFS 7.2 m vs. 13.7 m, p < 0.001; OS 21.7 m vs 26.2 m, p = 0.048; Figs. 3c, 4c) and luminal subtype (PFS 8.0 m vs. 12.3 m, p = 0.026; OS 21.9 m vs 29.9 m, p = 0.021; Figs. 3d, 4d) breast cancers, high sPD-L1 level remained significantly associated with poor PFS and OS. Here, ERBB2 is linked to breast cancer.