High Ly6K mRNA expression in breast cancer was significantly correlated with poor five-year overall survival (low Ly6K, n=51; high Ly6K, n=52; HR=1.25, p=0.021, HR=hazard ratio, n=number of patients) shown by PROGgeneV2 (Table S4, Figure 4A). Here, LY6K is linked to breast cancer.