CD4 and Parkinson disease: Interestingly, in mice, CD1d-mediated presentation of lipid antigens by regulatory B cells to invariant NKT cells resulted in suppressive iNKT capable of modulating pathological autoreactive Th17 and Th1 CD4 T cells.44 Our data therefore suggest that B cells with regulatory capacity may be beneficial in Parkinson’s disease, although whether that requires CD1d or iNKT activation by B cells or is due to direct effects on pathological T cell responses via IL10 production will need further study.