Together, the cerebral hemorrhage and cerebrovascular defects of zebrafish dyrk1aa mutants and the chemical screening revealed an important but less-known role of DYRK1A in in vivo vascular formation, which involves a mechanism that is mediated by calcium signaling, providing a potential therapeutic target for DYRK1A-related vascular disorders. The gene discussed is DYRK1A; the disease is vascular disorder.