SHH and central nervous system neoplasm: The recent edition of The World Health Organisation Classification of Tumors of the CNS tumors (WHO CNS5)3 recognizes 3 major ATRT subgroups ATRT-SHH (SHH), ATRT-TYR (TYR), and ATRT-MYC (MYC) with varying demographics4,5 Click or tap here to enter text.