CD206 is not present in monocytes, making it more specific to PVMs than CD163.22, 23 A very small portion of microglia may also express weak CD206 under naïve state (Figure 1D’’, field a), and after brain injury such as stroke and brain trauma, a subpopulation of microglia and infiltrating macrophages transiently express high level of CD206.24, 25 Lyve‐1 is a receptor for hyaluronan and is expressed on the lymphatic vessels and PVMs, but not monocytes or microglia,26, 27 making it a more specific PVM marker than CD163 and CD206 (Figure 1D’’, field b). Here, CD163 is linked to Stroke.