Topical administration of sodium butyrate (SB) reduced symptoms of psoriasis-like skin inflammationTopical SB increased the number and activity of Treg cells, IL-10 transcription, and decreased IL-17 transcription in the skin of a mouse modelSB increased the transcription of IL-10 and decreased the transcription of IL-6 and IL-17 in human skin biopsies. Here, IL17A is linked to psoriasis.