Next, we analyzed the GSE25066 dataset that contains 290 ER+/HER2- breast cancer patients treated with endocrine therapy.21,22 Kaplan-Meier survival curve analysis showed that high expression of PRCP, IGF1 and NRG1 significantly correlates with decreased RFS in the endocrine therapy treated patients (Figure 4a). This evidence concerns the gene ERBB2 and breast cancer.