Our findings confirm in vitro data by Jensen et al. [20] and further show that upregulation of monocytic ILT3 expression by IFN beta is not an in vitro artefact, but can also be found in patients with relapsing-remitting multiple sclerosis undergoing IFN beta therapy as demonstrated by quantitative PCR. This evidence concerns the gene LILRB4 and relapsing-remitting multiple sclerosis.