Examples are a molecular classifier for differential diagnosis of psoriasis and eczema using NOS2 and CCL2726,27, prediction of the response to anti-IL-17 therapies in psoriasis by IL-19 levels in serum28, as well as correlation of the severity of psoriasis with DEFB4A29 or the severity of AD with CCL17/TARC30. Here, IL17A is linked to Alzheimer disease.