To test whether human oligodendrocytes have, in principle, the capacity to react to IL-12 on a functional level, we differentiated human oligodendrocyte-like cells derived from the oligodendroglioma cell line SCC163 cells in vitro21 (Extended Data Fig. 5e,f) and treated these cells with IL-12p70, IL-12p80 or IL-23. Here, IL23A is linked to oligodendroglioma.