blood interleukin amount blood interleukin-4 amount circulating B-cell stimulatory factor-1 level circulating B-cell growth factor-I level VT:0008601 circulating B-cell stimulating factor-1 level EFO:0008184 circulating B-cell stimulatory factor 1 level circulating IL-4 level circulating B cell stimulatory factor-1 level circulating BSF-1 level The proportion, quantity, or volume in whole blood, serum, or plasma of a soluble factor produced by activated T-cells that induces the expression of MHC class II genes and FC receptors on B-cells and causes their proliferation and differentiation; it also acts on T-cells, mast cells and several other hematopoietic lineage cells. CMO:0003066 Trait.ontology circulating mast cell growth factor-2 level circulating IL4 level circulating B-cell growth factor-1 level circulating MCGF-2 level circulating BCGF-1 level circulating Binetrakin level circulating interleukin-4 level circulating B-cell proliferating factor level interleukin 4 measurement