CD63⁺ granule translocation is inhibited in Rac2^-/- neutrophils. Cytospins were prepared from freshly isolated BMNs treated with CB/fMLP (5 μM) for 15 minutes, stained with 10 μg/mL anti-CD63 as a primary granule marker (green), and counterstained with DAPI (blue) to show nuclear structure. Panels show representative images from (A) resting WT BMNs, (B) resting Rac2^-/- BMNs, (C) CB/fMLP-stimulated WT BMNs, and (D) CB/fMLP-stimulated Rac2^-/- BMNs, with the left panel in each case showing CD63 alone and the right panel showing combined images of CD63 immunoreactivity and DAPI nuclear stain. Original magnification, ×40.