IL17A and psoriasis: Currently, several groups of biological drugs are available for the treatment of psoriasis: anti-TNF (such as adalimumab, etanercept or infliximab), anti-IL12/23 (ustekinumab), anti-IL17 (secukinumab, ixekizumab), anti-IL17 receptor (brodalumab) and anti-IL23 (guselkumab, risankizumab and tildrakizumab).