In 9 of the 11 evaluable subjects, the severity of psoriatic plaques was reduced by the end of the study. Overall, 64% of the subjects (7/11) demonstrated a reduction in their IGA score during the 28-day treatment period. EISO treatment of the psoriasis skin model reverted psoriatic pathology as demonstrated by histologic characterization and the expression of keratinocyte proliferation markers Ki67 and psoriasin. It also suppressed the production in pro-inflammatory cytokines ENA-78, IL-6, IL-8, MCP-1, GM-CSF, and IL-1b. This evidence concerns the gene CSF2 and psoriasis.