The CCR4 is expressed in approximately 30–65% of PTCL tumor cells, including high expression (~ 65%) in ALK− ALCL, variable expression (30–40%) in PTCL-NOS, AITL, and transformed mycosis fungoides (MF), while rarely expressed in ENKTL or ALK+ ALCL [96]. This evidence concerns the gene ALK and anaplastic large cell lymphoma.