Chosen cell lines represent different subgroups of mTCL, in particular ALK+ anaplastic large cell lymphoma (ALCL), ALK− ALCL, PTCL not otherwise specified (PTCL‐NOS), hepatosplenic T‐cell lymphoma (HSTCL), cutaneous T‐cell lymphoma (CTCL) and natural‐killer/T‐cell lymphoma (NKTCL). This evidence concerns the gene ALK and primary cutaneous T-cell non-Hodgkin lymphoma.