Development of a microarray-based method to detect exposure of human basophils to IL-3

► A set of gene transcripts from human basophils is described that acts as a sensor of prior exposure to IL-3. ► The detection of IL-3 or IL-3-like changes is robust across microarray platforms. ► The changes detected by this transcript set occur quickly and are stable in time. ► The results suggest that the normal circulating basophil is balanced between no IL-3 and high levels of IL-3.