TBR1 and neoplasm: Additionally, one MB group 4 tumor (P2233_114T) presented a TBR1 mutation, another (P4551_203T) carried a tandem duplication of the SNCAIP gene, which leads to PRDM6 activation and is the most common distinctive genomic alteration described for MB group 4 [37], and one MB group 3 tumor (P1148_116T) harbored the hotspot insertion in KBTBD4 [36].