IL-13 Protein is a cytokine which is secreted by T helper type 2 (Th2) cells, CD4 cells, natural killer T cell, mast cells, basophils, eosinophils and nuocytes. IL-13 affects the morphology, growth, and surface antigen expression and phenotype of monocytes and elicits B cell proliferation. Animal-Free IL-13 Protein, Human (His) is the recombinant human-derived animal-FreeIL-13 protein, expressed by E. coli , with C-His labeled tag. This product is for cell culture use only.