To further confirm the C/EBPβ-dependent expression of DDX21, the isoforms LAP* and LAP, which have an activating transcriptional function, were overexpressed in the ALK- ALCL cell line Mac-1 and the ALK+ ALCL cell line SR786, which does not express C/EBPβ. This evidence concerns the gene ALK and anaplastic large cell lymphoma.