Two major immune system genes under investigation are interleukin-12 subunit beta ( IL12B ) on chromosome 5q , which expresses interleukin-12B; and IL23R on chromosome 1p, which expresses the interleukin-23 receptor, and is involved in T cell differentiation. Interleukin-23 receptor and IL12B have both been strongly linked with psoriasis.  T cells are involved in the inflammatory process that leads to psoriasis.  These genes are on the pathway that upregulate tumor necrosis factor-α and nuclear factor κB , two genes involved in inflammation.  Recently, the first gene directly linked to psoriasis has been identified. A rare mutation in the gene encoding for the CARD14 protein plus an environmental trigger was enough to cause plaque psoriasis (the most common form of psoriasis).  
Psoriasis is more of an inconvenience in most cases than it is threatening. However, it is a chronic systemic inflammatory disease for which there is no true cure. The itching and peeling of skin can lead to significant pain and self-esteem issues. By far, the patient's quality of life is affected most with plaque psoriasis. Self-consciousness and embarrassment about appearance, inconvenience, and high costs of treatment options all affect one's outlook when living with psoriasis. It has recently become apparent that many patients with psoriasis are predisposed to diabetes , obesity , and premature cardiovascular disease. It is important that such patients seek good overall medical care aside from simply treating their skin disease. Anxiety , depression , or stress may worsen symptoms and increase the tendency to itch. Most patients can expect significant improvement from the treatment of their psoriasis.