AFF4 (AF4/FMR2 Family Member 4) is a Protein Coding gene. Diseases associated with AFF4 include Chops Syndrome and Lymphoblastic Leukemia. Among its related pathways are Formation of HIV elongation complex in the absence of HIV Tat and Gene Expression. The protein encoded by AFF4 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 AFF4 and MLL gene on chromosome 11 is found in infant acute lymphoblastic leukemia with ins.