We performed survival analyses on patients with HER2+ BC and discovered that 8 of the 42 ER-DEGs had significant survival differences – they were EPGAM (p = 0.041), FGF9 (p = 0.017), POLR2K (p = 0.015), HRNR (p = 0.002), RANBP1 (p = 0.003), SF3B4 (p = 0.003), TAC1 (p = 0.024), and FZD5 (p = 0.001) (Figure 2d). This evidence concerns the gene FGF9 and breast cancer.