IL15 and psoriasis: The amounts of mRNA that are expressed for TNF-α, IL-23, IL-6, and IL-15, which are not only essential cytokines involved in psoriasis but also expressed in the A-431 cell line, were subjected to Real-time PCR in the presence of selected testing groups including; blank exosomes, free TFC, and TFC-Exo (50 μΜ) and control untreated cells for 24 hours.