Participates in at least several B-cell activation processes as well as of other cell types. It is a costimulator of DNA-synthesis. It induces the expression of class II MHC molecules on resting B-cells. It enhances both secretion and cell surface expression of IgE and IgG1. It also regulates the expression of the low affinity Fc receptor for IgE (CD23) on both lymphocytes and monocytes. Genetic variations in IL4 may be a cause of susceptibility to ischemic stroke (ISCHSTR); also known as cerebrovascular accident or cerebral infarction. A stroke is an acute neurologic event leading to death of neural tissue of the brain and resulting in loss of motor, sensory and/or cognitive function. Ischemic strokes, resulting from vascular occlusion, is considered to be a highly complex disease consisting of a group of heterogeneous disorders with multiple genetic and environmental risk factors. Belongs to the IL-4/IL-13 family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Cell cycle regulation; Cytokine; Motility/polarity/chemotaxis; Secreted; Secreted, signal peptide
Cellular Component: external side of plasma membrane; extracellular space
Molecular Function: cytokine activity
Biological Process: B cell activation; B cell costimulation; cholesterol metabolic process; defense response to protozoan; innate immune response in mucosa; microglial cell activation; myeloid dendritic cell differentiation; negative regulation of acute inflammatory response; negative regulation of chronic inflammatory response; negative regulation of macrophage activation; negative regulation of nitric oxide biosynthetic process; negative regulation of osteoclast differentiation; negative regulation of T cell activation; negative regulation of transcription, DNA-dependent; positive regulation of activated T cell proliferation; positive regulation of B cell activation; positive regulation of B cell proliferation; positive regulation of cell proliferation; positive regulation of chemokine biosynthetic process; positive regulation of defense response to virus by host; positive regulation of immunoglobulin production; positive regulation of interleukin-10 production; positive regulation of interleukin-13 production; positive regulation of isotype switching to IgE isotypes; positive regulation of isotype switching to IgG isotypes; positive regulation of mast cell degranulation; positive regulation of MHC class II biosynthetic process; positive regulation of peptidyl-tyrosine phosphorylation; positive regulation of protein amino acid phosphorylation; positive regulation of T cell differentiation; positive regulation of T cell proliferation; positive regulation of transcription factor activity; positive regulation of transcription from RNA polymerase II promoter; positive regulation of transcription, DNA-dependent; positive regulation of tyrosine phosphorylation of Stat5 protein; regulation of immune response; regulation of inflammatory response; regulation of proton transport; T-helper 1 cell lineage commitment; T-helper 2 cell differentiation