Classes characterized by specific genetic alterations, which are often associated with distinct methylation patterns, include MYCN amplification & isochromosome 17q in medulloblastoma groups 3 and 4, loss of chromosome 22 in atypical teratoid/rhabdoid tumor, MYB/MYBL1 alterations in angiocentric glioma, and C19MC::TTYH1 fusion in embryonal tumor with multilayered rosettes [27–31]. The gene discussed is TTYH1; the disease is embryonal neoplasm.