Nonetheless, the regulation of the TCR signaling by CD45 is likely less fundamental in ALK+ ALCL for two main reasons: i) the lack of LCK expression, the major substrate of CD45; ii) the control of the TCR pathway by oncogenic NPM-ALK that represses proximal TCR molecules and activates distal TCR related molecules (6). This evidence concerns the gene PTPRC and anaplastic large cell lymphoma.