A commentary on the structural and functional features of central nervous system (CNS) lymphatic vessels, published in Nature by Louveau et al. (2015), highlights the potential significance of the newly discovered meningeal lymphatic system in brain development. The article discusses the implications of this discovery for understanding autism spectrum disorder (ASD), which is associated with immune dysregulation and increased extra-axial cerebrospinal fluid (EAF). The authors suggest that impaired meningeal lymphatic drainage due to peripheral chronic infection or inflammation may contribute to increased EAF and cortical dysplasia in ASD. They also note that the presence of a functional lymphatic system in the CNS challenges previous assumptions about brain tolerance and immune privilege. The commentary emphasizes the importance of further research into the role of meningeal lymphatics in ASD pathogenesis. It also highlights the potential of transcranial ultrasonography as a non-invasive tool for evaluating EAF and assessing meningeal lymphatic drainage in ASD children. The authors conclude that the discovery of the meningeal lymphatic system may provide new insights into the mechanisms underlying ASD and other neurodevelopmental disorders.A commentary on the structural and functional features of central nervous system (CNS) lymphatic vessels, published in Nature by Louveau et al. (2015), highlights the potential significance of the newly discovered meningeal lymphatic system in brain development. The article discusses the implications of this discovery for understanding autism spectrum disorder (ASD), which is associated with immune dysregulation and increased extra-axial cerebrospinal fluid (EAF). The authors suggest that impaired meningeal lymphatic drainage due to peripheral chronic infection or inflammation may contribute to increased EAF and cortical dysplasia in ASD. They also note that the presence of a functional lymphatic system in the CNS challenges previous assumptions about brain tolerance and immune privilege. The commentary emphasizes the importance of further research into the role of meningeal lymphatics in ASD pathogenesis. It also highlights the potential of transcranial ultrasonography as a non-invasive tool for evaluating EAF and assessing meningeal lymphatic drainage in ASD children. The authors conclude that the discovery of the meningeal lymphatic system may provide new insights into the mechanisms underlying ASD and other neurodevelopmental disorders.