MKI67 and breast cancer: Multivariate COX regression analysis incorporated with cell proliferation marker Ki-67 also showed that high NFIB expression is correlated with worse DMFS (HR = 1.46, 95% CI: 1.05–2.05; p = 0.03) and worse RFS (HR = 1.46, 95% CI: 1.17–1.82; p < 1e-04) of HER2+ breast cancer patients but not with patients of other subtypes (Supplementary Fig. 6b), a result consistent with the univariate survival analysis (log-rank test).