IL17A and psoriasis: In this context, an increased transcript level of pro-inflammatory factors such as IL-6 is the essential hallmark of the disease (Grossman et al. 1989; Fujishima et al. 2010; Johnston et al. 2013) in addition to further described cytokines important in psoriasis pathogenesis such as TNF-alpha, IL-22 and IL-17 (Zheng et al. 2007; Nickoloff 2007).