Also, calprotectin (S100A8/ S100A9) upregulated in the inflamed skin of psoriatic patients serves as endogenous ligand for TLR4, and their binding further enhances inflammation in psoriasis patients (D'Amico et al., 2018[28]; Ehrchen et al., 2009[41]). The gene discussed is S100A9; the disease is psoriasis.