ROR1 and breast cancer: However, after adjustment for subtype, treatment, and RCB class, patients with HER2 + subtype tumors and minimal residual disease after treatment (RCB-0/I) had significantly worse EFS (HR = 3.46, 95% CI = 1.33–9.02, LRp = 0.01,) Table 1, if their breast cancers expressed high levels of ROR2. Inclusion of ROR1 in this analysis model did not change these findings but provided for a numerically larger hazard ratio in the HER2 + RCB-0/I group (HR = 4.87, 95%CI = 1.57–15.09, LRp = 0.004).