Animal-free Recombinant Human IL-4 also known as B cell-stimulatory factor-1. IL-4 is a monomeric, approximately 13 kDa and 19 kDa Th2 cytokine which shows pleiotropic effects during immune responses. Our IL-4 is produced in a human cell expression system with serum-free and chemically defined media. It has demonstrated greater stability under cell culture conditions making it ideal for efficient generation of Human Dendritic Cells.