Model for MN1 function in myeloid cells. A) Via p300/CBP MN1 is recruited to, and regulates the transcriptional activity of RAR/RXR and VDR/RXR heterodimers affecting the differentiation of myeloid progenitors via up- (a), or downregulation (b) of target genes. MN1 can also be recruited to other transcription factors (X) that bind p300/CBP, again affecting transcription of target genes. B) MN1 might also bind directly to transcription factors (Y), affecting the transcription of target genes. The interaction with Y might also be indirect, i.e. via another interacting protein than p300/CBP (not indicated).