WDR44 is an X-linked Rab11 effector protein that acts as a critical negative regulator of ciliogenesis while facilitating alternative protein export pathways. As a downstream effector of Rab11, WDR44 regulates intracellular membrane trafficking through multiple mechanisms 1. Akt-mediated phosphorylation of WDR44 promotes its binding to Rab11, which competitively inhibits formation of the ciliogenic Rab11-Rabin8-Rabin8IP-Rab11FIP3 complex, thereby suppressing ciliogenesis initiation 1. In parallel, WDR44 coordinates with GRAF proteins and ER-localized VAPA/VAPB to establish membrane contact sites that facilitate Rab8/10/11-dependent export of neosynthesized proteins including E-cadherin, MMP14, and CFTR 2. Pathogenic variants in WDR44's WD40-repeat domain cause a ciliopathy spectrum characterized by developmental delay, intellectual disability, hypotonia, and variable organ abnormalities 3. Disease-associated missense and nonsense variants impair protein folding and stability, leading to proteasomal degradation, while increased Rab11 binding correlates with ciliogenesis dysregulation 3. WDR44 also functions as a cytosolic regulator essential for AP-4-mediated trans-Golgi network export 4, indicating broader roles in secretory pathway organization. Additionally, WDR44 is phosphorylated by the kinase SGK3 at endosomal compartments, suggesting regulatory crosstalk with PI3K signaling 5.