SHH and central nervous system neoplasm: In the new version of WHO classification of the CNS tumors, MBs not belonging to the WNT or SHH group are designated as “non-WNT/non-SHH”, which is a combination of the established molecular subgroups “non-WNT/non-SHH group 3” and “non-WNT/non-SHH group 4” [8].