GARNL3 (GTPase activating Rap/RanGAP domain like 3) is a plasma membrane-localized protein with GTPase activator activity that regulates cellular signaling responses. In granulosa cells, GARNL3 expression is downregulated during in vitro culture, suggesting a role in cell signaling and response to external stimuli within the ovarian microenvironment 1. GARNL3 is located within a critical region on chromosome 9.3 implicated in neurodevelopmental disorders; reduced GARNL3 expression occurs in patients with microdeletions of this region who present with intellectual disability, developmental delay, microcephaly, and seizures of incomplete penetrance, though sequencing of GARNL3 in unrelated intellectual disability patients detected no causative mutations 2. In glioblastoma multiforme, GARNL3 emerged as a hub gene in co-expression network analysis with expression levels significantly correlated to WHO classification, suggesting potential utility as a biomarker 3. GARNL3 has been identified as a candidate gene for autosomal recessive neurodevelopmental disorders within previously reported intellectual disability microdeletion regions, with increased expression in developing and adult human brain structures 4. Additionally, GARNL3 was incorporated into a prognostic model for bladder cancer demonstrating strong predictive accuracy 5. These findings indicate GARNL3 participates in cellular signaling, neurodevelopment, and potentially in cancer progression, though its precise molecular mechanisms require further investigation.