The concentration dependence of the KDM degradation activities of these PROTACs is more consistent in MCF-7 with significant degradation of nuclear KDM5B (Figure 12a–b), which has been reported to play a significant role in breast cancer progression and metastatic behavior.39 In MDA-MB-231, DW-229 degraded KDM6B while it has little effects on KDM5B (Figure 12c). The gene discussed is KDM5B; the disease is breast cancer.