CXCR1 and relapsing-remitting multiple sclerosis: Neutrophils RRMS patients are not only more abundant but also express higher levels of TLR2, CD43, FPR1, and CXCR1, which support the hypothesis that neutrophils in RRMS are primed by the chronic inflammatory milieu, as these receptors are upregulated by priming agents [131, 132].