<p>Introduction: The objective of our study is to clarify the involvement of the HMGB1/RAGE/TLR4/NF-kB axis,</p><p>a crucial component in inflammation, in the etiopathogenesis of autism spectrum disorder (ASD).</p><p>Method: We analyzed the levels of HMGB1, RAGE, TLR4, and NF-kB in serum from 80 children (40 with</p><p>ASD and 40 controls). All participants’ sociodemographic characteristics were recorded. In order to</p><p>determine the severity of the disorder, the Aberrant Behavior Checklist, Childhood Autism Rating Scale, and</p><p>Autism Behavior Checklist were administered to the ASD group.</p><p>Result: While the soluble TLR4 level was significantly higher in the ASD group (p&lt;0.001), other parameters</p><p>examined did not show significant differences between groups. Furthermore, soluble TLR4 serum level was</p><p>positively correlated with Problem Behavior Checklist hyperactivity subscale scores (p¼0.031), and RAGE</p><p>serum level was negatively correlated with ABC Stereotype score (p¼0.001).</p><p>Discussion: It was thought that serum TLR4 levels may be important in the etiology of ASD. TLR4 levels are</p><p>linked to symptoms like hyperactivity in autism, which suggests that this parameter could be used as a</p><p>clinical guide. Further research is required to substantiate our discoveries and to clarify the involvement of</p><p>HMGB1, RAGE, TLR4, and NF-kB in the etiopathogenesis of ASD</p>