Positive feedback loop regulating IRF4 expression in PTCL.IRF4 is transcriptionally regulated by the alternative NF-κB pathway (RelB/p52), augmented in some cases by the intronic IRF4 SNP rs12203592-T. IRF4 CNAs are associated with IRF4 protein expression, but their contribution to IRF4 transcription is not known. IRF4 drives Myc expression and tumor proliferation. In addition, IRF4 increases CD30 expression, leading to activation of NF-κB and perpetuation of IRF4 expression. Numbers in parentheses indicate figure numbers corresponding to relevant experiments.