2.2 Psoriasis severity evaluation
To evaluate the severity of inflammation in the ears and neck skin of mice, we used an objective scoring system based on the clinical Psoriasis area and severity index (PASI). Erythema, scaling, and thickening were scored independently on a scale of 0 to 4: 0, none; 1, slight; 2, moderate; 3, marked; or 4, very marked (van der Fits et al., 2009).