Consistent with the association between stromal TILs and more favorable prognosis in BC29,30, we found a significant univariate correlation between presence of stromal TILs and better overall survival in our BC patient cohort (HR = 2.35, CI 95% 1.19–4.30, p = 0.009) in all patients and in HER2+ patients (HR = 3.12, CI 95% 0.97–8.79, p = 0.038), with a consistent behavior, albeit not statistically significant, in the subpopulations of HER2− patients (HR = 1.89, CI 95% 0.77–4.02, p = 0.13) (Supplementary Fig. 1). This evidence concerns the gene ERBB2 and breast cancer.