TREM2 and triple-A syndrome: Opposite to the Trem2 KO, sTREM2 overexpression increased elastin degradation (Figure 8H,I) and had a trend to increase macrophage number in the aortic wall (Figure 8J,K), potentially due in part to enhanced macrophage survival.[80, 84] The results indicated that sTREM2 plays a detrimental role in AAA development.