CD14 and triple-A syndrome: Next, we investigated the role of CD14 in aortic macrophage precursor recruitment after only 4 days of AngII infusion, early during the course of AAA formation, using an in vitro assay.22,29 Avid binding of CD14+/+, but not CD14−/−, macrophage precursors to aortic explant adventitia was detected (Figure 2E) in comparison with the luminal surface.