S100A7 and psoriasis: To examine the effect of TLR activation on keratinocytes, the epidermal models were either treated with the TLR2 agonist Pam2CSK4 or the TLR3 agonist poly(I:C) and subsequently analyzed for the expression of S100A7, an antimicrobial peptide and prominent psoriasis marker, by immunohistochemical staining and western blot.