TRAF1 and anaplastic large cell lymphoma: Interestingly, expression of the TRAF1-ALK fusion protein leads to constitutive activation of the ALK and NF-κB pathways as demonstrated by the elevated levels of phosphorylated ALK (pALK) and STAT3 (pSTAT3) as well as nuclear p50 NF-κB1 and p52 NF-κB2 in ALCL cells (18).