ROR1 and neoplasm: Kaplan–Meier exploratory analysis by ROR1 above or below the median level indicated that HR + HER2- patients with high-level ROR1 at baseline and high-tumor burden after treatment (RCB-II/III) had significantly worse EFS, (HR = 0.55, 95% CI = 0.33–0.9, LRp = 0.02), Fig. 3a.