In this piece for Nature Reviews Drug Discovery, Nick Kapolka and I discuss the druggability of the understudied GPCR, hydroxycarboxylic acid receptor 3 (HCAR3), which we recently discovered is activated by the tryptophan pathway metabolite kynurenic acid, a potent immunomodulator. The full text can be found here: https://www.nature.com/articles/d41573-020-00173-2.
