Efalizumab, a humanized monoclonal antibody against LFA-1, has shown a positive response to psoriasis through potently inhibiting the proliferation and cytokine production of human T cells by downregulating the co-stimulatory molecules ICOS, OX40, CD27, and 4-1BB (Kuschei et al., 2011). This evidence concerns the gene ITGAL and psoriasis.