Diagram depicting a network of transcriptional interactions driving ATL maintenance that is initiated by HTLV-1 infection and then propagated by somatic mutations. The gray box indicates the network motif identified by Wong et al called a “coherent feed-forward loop” that is used by normal T cells to rapidly expand to fight foreign invaders but is hijacked and constitutively activated in ATL cells. This loop consists of the top-tier transcription factor NF-kB inducing the second-tier transcription factor IRF4 followed by cooperative binding and activation by the 2 factors of super-enhancers associated with major oncogenes (MYC, CCR4, and BIRC3).