EPO and multiple sclerosis: In addition, endogenous EPO exhibits immunomodulatory effects by reducing the proliferation of conventional T cells without inducing apoptosis, while simultaneously promoting proliferation of regulatory T cells (Treg) and decreasing B cell numbers (Cravedi et al., 2014; Purroy et al., 2017; Peng et al., 2020), which may be beneficial in chronic inflammatory diseases of the CNS, e.g., multiple sclerosis (MS) (Baecher-Allan et al., 2018).