CD8A and malaria: Characterization of malaria antigen-specific CD8+ T cells by this method is limited, however, as their effector function might be due to cytokines distinct from those being measured (for example, by flow cytometry), or to non-cytokine-related mechanisms such as Fas/FasL-mediated induction of apoptosis or the direct killing of hepatocytes through release of perforin and granzyme.