## 2 Discussion
### Interleukins (IL)  
Interleukins are cytokines that play an essential role in the differentiation, proliferation, migration, adhesion, and maturation of immune cells. They can be both pro-inflammatory and anti-inflammatory. By binding to interleukin receptors, interleukins trigger a cascade of reactions that constitute the immune system [12]. The pro-inflammatory mediators associated with psoriasis are IL1B, IL2, IL6, IL12, IL15, IL17, IL18, and IL20. Specifically, IL1B encodes a cytokine produced by activated macrophages and plays an important role in the inflammatory response. IL2 encodes a cytokine important for the proliferation of T and B lymphocytes. IL6 encodes a cytokine that induces inflammatory responses through IL6 Ra and the maturation of B cells. IL12 induces Th1 cells to produce IFN-\(\gamma\). IL15 encodes a cytokine that regulates T-cell and natural killer activation and proliferation and induces the activation of janus kinases (JAK), as well as the phosphorylation and activation of STAT3, STAT5, and STAT6 proteins. IL17 is produced due to IL23 activation of Th17 cells. IL17 is a key mediator of autoimmunity. IL18 stimulates the production of IFN-\(\gamma\) in Th1 cells. IL20 encodes a cytokine structurally related to IL10 and transduces its signal through STAT3 in keratinocytes [4].  
The anti-inflammatory genetic mediators associated with psoriasis are IL1 RN, IL4, IL10, IL13, and IL19. IL1 RN inhibits IL1 and modulates the immune and inflammatory responses. IL4 is a pleiotropic cytokine involved in the modulation of Th2 immune responses. Its receptor also binds IL13, which may contribute to many overlapping functions of this cytokine and IL13. IL10 encodes a cytokine produced by monocytes and lymphocytes that downregulated the expression of Th1 cytokines and blocks NF-kB activity. It further enhances B-cell survival, proliferation, and antibody production and regulates the JAK-STAT signaling pathway. IL13 encodes a cytokine produced by activated Th2 that is involved in the maturation and differentiation of B cells and downregulates macrophage activity and inhibits the production of proinflammatory cytokines and chemokines [4]. IL19 is a member of the IL10 cytokine subfamily with a role in inflammatory responses.  
Several genetic variants among ILs are associated with psoriasis development and progressions. The rs2275913 single nucleotide polymorphism (SNP) in the IL17A gene, featuring a substitution of guanine (G) with adenine (A), was linked to an increased risk of psoriasis by enhancing IL17A production and promoting inflammation. Furthermore, the rs3212227 SNP in the IL12B gene, characterized by a substitution of thymine (T) with cytosine (C), is associated with psoriasis susceptibility by upregulating IL12B expression, which contributes to the dysregulated immune response observed in psoriasis. Additionally, the rs1800872 SNP in the IL10 gene, featuring the G allele, was associated with an elevated risk of psoriasis by downregulating the production of IL10, an anti-inflammatory cytokine involved in immune regulation. These genetic variations provide insight into the role of ILs in psoriasis pathogenesis [3; 4; 9; 10]. However, further research is needed to fully understand their functional implications and their precise contribution to the disease course.