CASZ1 (castor zinc finger 1) is a transcriptional activator that plays critical roles in neural, cardiovascular, and endocrine development 1. The protein functions as a DNA-binding transcription factor that regulates cell fate determination and tissue morphogenesis across multiple organ systems 1. In neural development, CASZ1 is essential for inner hair cell fate stabilization in the cochlea, where loss of function causes transdifferentiation of inner hair cells to outer hair cells and compromises outer hair cell survival 2. The protein also regulates neuron differentiation and has been identified as a risk gene for neurodevelopmental disorders, with de novo mutations showing significant enrichment in affected patients 3. In cardiovascular development, CASZ1 controls cardiomyocyte differentiation and vascular morphogenesis 1. Additionally, CASZ1 modulates aldosterone biosynthesis and mineralocorticoid receptor activity, with genome-wide association studies identifying it as a risk locus for primary aldosteronism 45. Overexpression of CASZ1 suppresses aldosterone production in adrenocortical cells 4. The gene is located in the 1p36 region, and deletions contribute to 1p36 deletion syndrome phenotypes 6. In cancer contexts, CASZ1 shows tissue-specific effects, acting as either a tumor suppressor or oncogene depending on the malignancy type 78.