Probably involved in transcriptional regulation. In vitro or as fusion protein with KMT2A/MLL1 has transactivation activity. Binds to cruciform DNA. In cells, binding to unmodified histone H3 regulates DOT1L functions including histone H3 'Lys-79' dimethylation (H3K79me2) and gene activation (PubMed:26439302). Self-associates. Interacts with FSTL3 isoform 2; the interaction enhances MLLT10 in vitro transcriptional activity and self-association. Interacts with YEATS4. Interacts with SS18. Interacts with DOT1L; this interaction also occurs with the KMT2A/MLL1 fusion protein. Interacts with histone H3; interaction is necessary for MLLT10 binding to nucleosomes; interaction is inhibited by histone H3 'Lys-27' methylations (H3K27me1, H3K27me2 and H3K27me3) amd acetylation; interaction stabilizes association of MLLT10 at chromatin; interaction is essential for histone H3 'Lys-79' dimethylation (H3K79me2) (PubMed:26439302). Expressed abundantly in testis. A chromosomal aberration involving MLLT10 is associated with acute leukemias. Translocation t(10;11)(p12;q23) with KMT2A/MLL1. The result is a rogue activator protein. A chromosomal aberration involving MLLT10 is associated with diffuse histiocytic lymphomas. Translocation t(10;11)(p13;q14) with PICALM.