Our colorful cover image shows a microarray measuring the expression level of 609 microRNAs (miRNAs) between mice sensitive to experimental autoimmune encephalomyelitis (EAE, left) and those resistant to EAE (right). EAE was induced by subcutaneous immunization of MOG35–55 peptide in wild-type C57BL/6 mice (which are sensitive to EAE induction) and CD44−/− C57BL/6 mice (which are rendered resistant to EAE induction by CD44 ablation). The image is taken from Guan et al. (pp. 104–114) in which the authors show that miRNA let-7e is significantly upregulated in CD4+ T cells and infiltrated mononuclear cells of the central nervous system during EAE induction. The authors further show that let-7e silencing inhibits encephalitogenic Th1 and Th17 cells and attenuates disease, while overexpression of let-7e enhances Th1 and Th17 cells and aggravates EAE. Collectively, these findings highlight let-7e as a new miRNA involved in the regulation of encephalitogenic T-cell differentiation.