The transcriptional patterns of mature normal PB neutrophils (granulocytes) was examined and used as a control against which the transcriptional programs of cultured granulocytes and granulocytic cells lines can be compared. Experiment Overall Design: RNA was extracted from peripheral blood neutrophils. Three biological replicate experiments were analyzed and approximately 67% of the samples were technically replicated. Hybridizations were performed in a reference design with all samples labeled with Cy3 and a reference RNA pool labeled with Cy5.