The protein encoded by this gene belongs to the AF4 family of transcription factors involved in leukemia. It is a component of the positive transcription elongation factor b (P-TEFb) complex. A chromosomal translocation involving this gene and MLL gene on chromosome 11 is found in infant acute lymphoblastic leukemia with ins(5,11)(q31,q31q23).,AFF4,AF5Q31,CHOPS,MCEF,Epigenetics & Nuclear Signaling,Transcription Factors,Cell Biology & Developmental Biology,Cell Cycle,Cyclins,AFF4