ESR1 and neoplasm: Moreover, the results showed this 9 RNA classifier has a significant prognostic value for both ER+ (hazard ratio (HR) = 3.28 (CI: 1.76 – 6.11), p = 0.0002, Figure 6B) and ER- tumours (hazard ratio (HR) = 3.41 (CI: 1.28 – 9.06), p = 0.013, Figure 6C).