Interestingly, high levels of IRF4 protein exist in Epstein-Barr virus (EBV)-transformed cells and associated B-cell lymphomas with Type 3 latency [17]–[20], as well as in Human T-cell Leukemia Virus-1 (HTLV1)-infected cell lines and associated Adult T-cell Leukemia (ATL) [21]–[25]. Here, IRF4 is linked to B-cell non-Hodgkin lymphoma.