To investigate whether α5β1 integrin has a potential as a drug target for psoriasis treatment, the α5β1 integrin-binding peptide, C16, was used to obstruct the HaCat keratinocyte cellular responses induced by fibronectin (Fn) in culture and psoriasis-like skin inflammation induced in mice by imiquimod (IMQ). The gene discussed is FN1; the disease is psoriasis.