Autism spectrum disorders (ASD) are neurodevelopmental disorders that affect around 1% of the population. Matenral immune activation (MIA) during pregnancy is a risk factor for ASD in children (Han 2021), mediated by maternal secretion of IL-17a, which disrupts neurodevelopment (Choi 2016). MIA causes a long-lasting disruption of the Tregs/Th17 balance in offspring (decrease in anti-inflammatory Tregs/increase in pro-inflammatory Th17s) via epigenetic mechanisms (Lim 2021; Ellul 2021). In a mouse model of MIA, adoptive transfer of Tregs was able to normalise autistic behaviour, highlighting the importance of Tregs in maintaining the autistic phenotype (Xu, 2021). In this same model, we have shown that IL-2fd (i) stimulates Tregs, (ii) corrects meningeal inflammation (iii) normalises synaptic connectivity and (iv) normalises autistic behaviour in the offspring (Ellul 2025). In humans, the use of low doses of interleukin-2 (IL2-fd) (ILT-101) leads to activation and selective expansion of Tregs and a reduction in Th17 (Klatzmann 2015), including in children (Rosenzwajg 2020). We hypothesise that the use of IL2-fd (ILT-101) in ASD patients born to mothers with a history of MIA could correct the Tregs deficiency and improve autistic symptoms.