DNase I Hypersensitivity Patterns of the Serglycin Proteoglycan Gene in Resting and Phorbol 12-Myristate 13-Acetate-stimulated Human Erythroleukemia (HEL), CHRF 288-11, and HL-60 Cells Compared with Neutrophils and Human Umbilical Vein Endothelial Cells*