MAPT and dementia: Recent work in mice expressing dementia-associated mutant tau indicates that the complement system is involved in neurodegeneration; however, reducing microglial numbers by inhibiting colony-stimulating factor 1 receptor (CSF1R) did not ameliorate degenerative phenotypes (Bennett et al., 2018, Dejanovic et al., 2018, Litvinchuk et al., 2018).