The coding region of mouse PON1 was placed under the control of the macrophage-specific human scavenger receptor A (MSR1) gene regulatory elements and the human growth hormone polyadenylation signal. Analysis of mRNA from transgenic mice showed that the construct was expressed only in circulating monocyte/macrophages and tissues containing resident macrophages (i.e., liver, lung, spleen, but not in heart, kidney, brain, or skeletal muscle). (J:118732)