Since tumor angiogenesis is also crucial for tumor metastasis,24 we further evaluated the role of exosomal BCYRN1 in the angiogenesis of BCa by conducting the tube formation and migration assays using HUVECs, which revealed that the CM and isolated exosomes from BCYRN1‐silenced or overexpressing UM‐UC‐3 cells have no significant effect on the tube formation and migration of HUVECs (Figures S3A‐S3F). The gene discussed is BCYRN1; the disease is neoplasm.