The four different macrophage populations expressed a common macrophage marker, Ms4a6d, and displayed a transitional gradient from early to later defense against viral infection, with Mac1 having the highest expression of Cybb and lowest expression of Tgfb1 and Slamf7 and Mac4 showing the highest expression of Slamf7 and Tgfbi and the lowest expression of Cybb (Fig. 2B). This evidence concerns the gene TGFB1 and viral infectious disease.