Fig 2: (A) Immunohistochemical detection (brown stain) of the proinflammatory markers induced nitric oxide synthase (iNOS) and cyclooxygenase 2, and the anti-inflammatory markers mannose receptor 1 and arginase 1 (Arg1) at days 7, 10, 14, and 21 after intracerebral injection of 5 × 103 4T1-GFP cells (sections counterstained with cresyl violet). (B) Detection of pro- and anti-inflammatory microglia/macrophages in the metastatic brain by immunofluorescent colocalization of Iba1 with either iNOS (top panel) or Arg1 (bottom panel) at days 7, 14, and 21 after intracerebral injection of 5 × 103 4T1-GFP cells. Arrows show areas of colocalization, which are magnified in the insets. Scale bars 20 µm (A), 50 µm (B), or 25 µm [(B) insets].