IL1B and Stroke: Finally, as shown in Figure 8b–e, the microglia polarization induced by brain PBM was confirmed by the increased production of IL‐1β (i.e., proinflammatory cytokine) and reduced arginase‐1 and IL‐10 (i.e., anti‐inflammatory cytokines), which were markedly reversed in the PBM‐treated group at 7 days post stroke.