IL4 and psoriasis: This study explores regenerative therapies—exosomes, mesenchymal stem cells (MSCs), epigallocatechin-3-gallate nanoparticles (EGN), and EGN-loaded exosomes (EGN-Exo)—in regulating psoriasis-related markers (IL-6, IL-4, Bcl-2, Bax, NF-κB, CDC25B).