SECTM1 and dilated cardiomyopathy: Impressively, we found that human SECTM1 was the highest enriched in macrophages among all cardiac cell types (Figure 1A), and the average expression levels of SECTM1 were significantly reduced by 0.82-fold in cardiac macrophages only within human dilated cardiomyopathy (DCM), compared with healthy nonfailure (NF) hearts (Figure 1B).