Key Clinical Message: Baricitinib, a Janus kinase inhibitor (JAK‐inhibitor), seems to contribute to an improvement of a child affected by Aicardi‐Goutières syndrome (AGS), reducing the interferon score and determining a recovery of cognitive, communicative, and relational dysfunctions, while the gross motor deficit persisted. We report the treatment response to baricitinib, a JAK‐inhibitor, in a 4‐year‐old girl affected by Aicardi‐Goutières syndrome (AGS2, RNASEH2B mutation). Using quantitative measures, we detected a significant amelioration characterized by a complete recovery of cognitive, communicative, and relational skills after 8 and 16 months from the beginning of therapy. [ABSTRACT FROM AUTHOR]