Comparison of the deformability of P knowlesi iRBCs from humans and M fascicularis. (A) Human iRBCs (first two columns) and M fascicularis iRBCs (last column) before (upper row) and after (lower row) micropipette aspiration. (B) Deformability, as measured by micropipette aspiration, of iRBCs and uRBCs from P knowlesi–infected humans and M fascicularis monkeys compared with healthy human and monkey controls. An increase in MSM reflects a decrease in deformability. Scale bar = 5 μm.