Plays a role in transcriptional regulation as a repressor that inhibits monoamine oxidase A (MAOA) activity and gene expression by binding to the promoter. Plays an important oncogenic role in mediating the full transforming effect of MYC in medulloblastoma cells (By similarity). Involved in apoptotic signaling pathways; May act downstream of P38-kinase and BCL-2, but upstream of CASP3/caspase-3 as well as CCND1/cyclin D1 and E2F1. Interacts with MYC (By similarity). Interacts (via IBM motifs) with PSIP1 (via IBD domain); phosphorylation increases its affinity for PSIP1 (By similarity). Associates with chromatin. Translocates from cytoplasm to nucleus under dexamethasone induction (By similarity). Expressed in all tissues but not detected in total brain. Phosphorylation increases its interaction with PSIP1.