EVI5L (ecotropic viral integration site 5 like) is a GTPase-activating protein (GAP) with broad substrate specificity that functions as a negative regulator of ciliogenesis. As a TBC domain-containing protein, EVI5L exhibits RabGAP activity toward Rab10 and Rab23, regulators of intracellular trafficking 1. The primary mechanism of EVI5L's anti-ciliogenic function involves suppression of primary cilium assembly; overexpression of EVI5L blocks ciliogenesis, while reduced EVI5L expression restores cilium formation and hedgehog (Shh) pathway signaling 2. EVI5L expression is negatively regulated by TGIF1/TGIF2 transcription factors, which bind conserved regulatory elements upstream of the EVI5L gene 2. Dysregulation of EVI5L has been associated with multiple disease states: it was identified as a potential diagnostic biomarker in idiopathic pulmonary hypertension with metabolic syndrome 3, and differential EVI5L expression was detected in calcium oxalate kidney stone patients 4. The broader EVI5 family has been implicated in multiple sclerosis susceptibility 1. These findings suggest EVI5L's role as a critical modulator of ciliary development with potential relevance to multiple human pathologies involving ciliary dysfunction and metabolic dysregulation.