Transcription factor, which activates RAG1, and possibly RAG2, transcription. Through the regulation of RAG1/2 expression, may regulate thymocyte maturation (PubMed:28344082). Along with NIPBL and the multiprotein complex Integrator, promotes cortical neuron migration during brain development by regulating the transcription of crucial genes in this process. Preferentially binds promoters containing paused RNA polymerase II. Up-regulates the expression of SEMA3A, NRP1, PLXND1 and GABBR2 genes, among others (PubMed:28041881). Involved in regulation of myoblast proliferation during myogenesis. Interacts (via N-terminus) with NIPBL (PubMed:28041881). Interacts with the multiprotein complex Integrator (PubMed:28041881). Expressed in myoblasts (PubMed:28344082). Expressed in neurons in various brain regions, including striatum, prefrontal cortex, olfactory bulb, midbrain, cerebellum and hippocampus (PubMed:25921068). Expressed in neural stem cells (at protein level) (PubMed:28041881). Expressed in thymocytes (PubMed:23076336). Expressed in the developing brain at 12.5 dpc. At 14.5 dpc, becomes enriched in the ventricular zone and later, restricted to the progenitor population as cortical neurogenesis peaks. At this stage, not detected in the subventricular zone/intermediate zone (SVZ/IZ). At later stages, detected in the neurons of the cortical plate and in stem cells near the ventricular surface. Down-regulated by ZNF608 (PubMed:23076336). Isoform 2 is up-regulated during neuronal differentiation (PubMed:25921068). Produced by a back-splicing reaction which joins the 5'-splice site of the first coding exon with the 3'-splice site of the upstream intron resulting in a circular RNA, called circ-ZNF609. The translation starts with the same initiator methionine as that of the linear transcript encoding isoform 1. The stop codon is created upon circularization. Truncated N-terminus.