Imiquimod is used in the management of both precancerous and cancerous skin lesions, but through its agonistic effects on Toll-like receptor (TLR)7 and TLR8 signalling can induce psoriasis-like reactions that can be recapitulated as a type 17 inflammatory phenotype in mice.72 By employing this imiquimod approach, hCD1a-Tg mice demonstrated epidermal hyperplasia, exaggerated oedema, erythema and scaling that were suppressed through anti-CD1a blockade.10,17 Here, CD1a inhibition was associated with a reduction in granulocytes and production of IL-17A, IL-17F and IL-22 by T cells. The gene discussed is IL17A; the disease is psoriasis.