High Ly6E mRNA expression in breast cancer was significantly correlated with poor five-year overall survival with restriction of estrogen receptor positive breast cancer (low Ly6E, n=112; high Ly6E, n=113; HR=1.39, p=0.002), with restriction of progesterone receptor positive breast cancer (low Ly6E, n=112; high Ly6E, n=113; HR=1.39, p=0.002) or without restriction (low Ly6E, n=15; high Ly6E, n=16; HR=2.73, p=0.02), and five-year distance metastasis free survival (low Ly6E, n=112; high Ly6E, n=113; HR=1.44, p=0.000) shown by PROGgeneV2 (Table S2, Figure 2B). Here, ESR1 is linked to breast cancer.