Bystander cells were seen in 16 T-cell lymphomas (2 ALK-negative anaplastic large cell lymphoma (ALK(-) ALCL), 9 AITL, 1 enteropathy-associated T-cell lymphoma (EATL), 1 monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), 2 peripheral T-cell lymphoma (PTCL)-NOS and 1 HTLV1 associated adult T-cell leukaemia/lymphoma). This evidence concerns the gene ALK and anaplastic large cell lymphoma.