MAPT and Alzheimer disease: The C3a receptor antagonist SB290157 is able to decrease amyloid load, the Aβ42/40 ratio [371], and microglial proliferation [372], as well as tau hyperphosphorylation [373], while the inhibition of C5a receptor 1 with the cyclic hexapeptide PMX205 decreased amyloid β and tau accumulation, reduced glial activation, and improved cognition in murine AD models [374].