DNMBP (dynamin binding protein) functions as a guanine nucleotide exchange factor (GEF) for CDC42, regulating multiple cytoskeletal processes critical for epithelial cell organization and development 12. The protein plays essential roles in maintaining apical junction structure through F-actin organization 12, controlling spindle orientation during lumenogenesis 3, and supporting ciliogenesis. DNMBP is required for normal nephrogenesis, with reduced expression impairing differentiation of distal and connecting tubules while causing glomus and ciliary defects 4. Under hyperosmotic stress, the ubiquitin ligase Nedd4-2 promotes DNMBP localization to P-bodies, facilitating CDC42 activation and downstream p38-MAPK signaling 5. In disease contexts, DNMBP has been implicated in late-onset Alzheimer's disease, with SNPs in the gene showing association with AD risk in Japanese and Belgian populations, particularly in APOE epsilon4-negative individuals 67, though findings have not consistently replicated in Caucasian populations 8. Additionally, the DNMBP-AS1 long non-coding RNA regulates metabolic reprogramming in colorectal cancer through a competing endogenous RNA network 9 and promotes prostate cancer progression via miR-6766-3p/LCLAT1 regulation 10. DNMBP mutations are associated with cataract 48, indicating roles in lens development.