C3 and Granuloma: C3 (m/z = 2,217.25) was mainly expressed in the periphery of the granulomas from cattle (Figure 7B); in accordance with the MALDI-MSI image, C3 immunolabeling was found in the cytoplasm of epithelioid macrophages and multinucleated giant cells of granulomas with lack of expression at the necrotic core (Figure 7C).