Here we investigated the prognostic value of HK2 in a cohort of /ER+/HER2+ breast cancers and identified that higher expressing HK2 tumors are characterized by reduced overall survival (OS, hazard ratio (HR) = 8.26, p = 0.001; Figure 8A) and relapse-free survival (RFS, HR = 2.33, p = 0.041; Figure 8B). This evidence concerns the gene ESR1 and breast cancer.