Constitutive activation of the AP-1 TF family members FRA-2, JUNB, JUN, ATF-3 and BATF-3 is observed in nearly all ALCL cases, regardless of the ALK status [71,118,119,120], whereas genomic gains of the FRA-2 and JUNB loci are described in some ALCL cases [121]. This evidence concerns the gene JUND and anaplastic large cell lymphoma.