A study investigated the epidermal expression of pattern recognition receptors (PRRs) and associated defense molecules in healthy human skin, atopic dermatitis (AD) and psoriasis.Genes differentially induced in psoriatic skin were CLEC7A, TLR4 and MRC1. Those for AD were MRC1, 1L1Rn and ILbeta1. In cultured primary human keratinocytes, dectin-1 expression was induced by both interferon- alpha and -gamma and by Th17 cytokines. No response by keratinocytes was seen with beta-glucan or heat-killed Candida albicans nor was synergy seen with TLR2/TLR5 ligands. Upregulation of dectin-1 in psoriatic lesions appears to be under the control of psoriasis-associated cytokines and deserves further study (de Konig, H. et al. J Invest Dermatol 2010, 130: 2611).