The observation that AGT-4, a structurally similar compound, did not upregulate the Treg proportion can be explained by the fact that agonist activity does not necessarily correlate with Treg promotion.1 For example, AHR agonist FICZ induces Th17 cells in vivo and therefore exacerbates encephalomyelitis in mice [8]. The gene discussed is AHR; the disease is encephalomyelitis.