Interestingly, the MB-G3 PDOX SJMBG3-16-08522 exhibited both MYC amplification and an indel in KMT2D/MLL2 that were not detected in the primary tumor, and the SJATRTSHH-14-8191 primary tumor lacked the focal CDKN2A/B deletion and BRCA2 and TSC1 mutations that were detected in the corresponding PDOX. The gene discussed is KMT2D; the disease is neoplasm.