CIBAR1 (CBY1 interacting BAR domain containing 1) is a BAR domain protein with critical roles in mitochondrial organization and ciliogenesis. As a membrane-organizing protein, CIBAR1 binds negatively charged phospholipids including cardiolipin and phosphatidylinositol 4,5-bisphosphate, inducing membrane curvature and tubulation essential for maintaining mitochondrial cristae ultrastructure 1. Beyond mitochondrial function, CIBAR1 plays a crucial role in primary cilia assembly and ciliogenesis 23, with evidence suggesting involvement in limb development through this ciliary pathway 3. CIBAR1 exhibits context-dependent subcellular localization that determines its biological functions; when localized to centrioles/basal bodies, it facilitates ciliogenesis, while other localizations may support alternative functions 4. The gene's clinical significance is underscored by its association with postaxial polydactyly type A9 (PAPA9), a non-syndromic digit anomaly 5. Disease-causing variants in CIBAR1 result in reduced expression and structural destabilization 5, with mutations causing developmental abnormalities linked to defective primary cilia formation 67. CIBAR1 also functions as a membrane recruitment factor for RabGEF complexes involved in intracellular trafficking 8, highlighting its multifunctional role in cellular organization.