LZTR1 and Down syndrome: LZTR1(leucine-zipper transcription regulator 1) is detected asa mutational cancer driver gene in GBM.1 A recent comprehensive molecular characterization of ubiquitin pathwayfrom 9125 tumor samples across 33 cancer types also found that LZTR1is among the frequently mutated genes.1,2 Further, heterozygousgermline loss-of-function LZTR1 variants have been linked to Schwannomatosiswhereas rare variants of LZTR1 were identified in individuals withNoonan syndrome (NS), a development disorder, caused by mutationsin components of the RAS/MAPK signaling pathway (i.e., RASopathies).3−5