GSE1 and neoplasm: Among these adult patients, co-occurring mutations are found commonly in candidate genes, including DDX3X, an RNA helicase; genetic suppressor element 1 (GSE1), a coiled-coiled protein known to interact with HDAC1 (Bantscheff et al., 2011); and lysine demethylase 3B (KDM3B), a demethylase with both tumor-suppressive and tumor-promoting effects (Kim et al., 2012, Xu et al., 2018).