A peculiar and severe syndrome among HAIDs which occurs in very young children is STING (stimulator of interferon genes)-associated vasculopathy with onset in infancy, named SAVI and caused by gain-of-function mutations in the TMEM173 gene, which encodes the STING protein: STING activation is followed by constitutionally increased interferon-β transcription and a typical “interferon signature” in the blood [33]. Here, STING1 is linked to STING-associated vasculopathy with onset in infancy.