As further evidence of a defect in TCR signalling, ZAP-70 is lost in anaplastic large-cell lymphoma compared with other T-cell lymphomas.143 Overall, ZAP-70 is detected in 25–30% of anaplastic large-cell lymphomas (8–25% of ALK+ and 20–41% ALK–) versus 59–74% peripheral T-cell lymphomas NOS and 29–57% of primary cutaneous (PC) anaplastic large-cell lymphomas.143,144. Here, ALK is linked to anaplastic large cell lymphoma.