The phagocytosis of neural membranes and synapses labelled with C1q-C3 by activated microglia is seen in MS and its models, where reducing complement activation or increasing its clearance, protects neurites and synapses and preserves neurological function (Hammond et al., 2020; Werneburg et al., 2020; Gharagozloo et al., 2021; Ramaglia et al., 2021). Here, C3 is linked to myeloid sarcoma.