Therefore, these distinct pharmaceutical approaches to reduce C5aR1 activation may represent useful mechanisms to modulate resident microglia and other C5aR1 expressing cells in MS (Vergunst et al., 2007; Michailidou et al., 2018; Carpanini et al., 2019; Schartz and Tenner, 2020). Here, C5AR1 is linked to myeloid sarcoma.