CD40LG and Alzheimer disease: B1 cells, which make IgM and are considered more “innate-like” in function, have been implicated in amyloid-beta clearance in people (Agrawal et al., 2018) and mice (Baulch et al., 2020): both B1 and IgM are decreased in an AD-relevant mouse model (Baulch et al., 2020).