TARP and anaplastic large cell lymphoma: However, subsequent analysis revealed that a slight majority of these 6p25.3 rearrangements in ALCL (both primary cutaneous and ALK-negative systemic) involve DUSP22 [48], while fewer (~30%) do indeed involve IRF4. DUSP22 is a dual-specificity phosphatase that inhibits T-cell antigen receptor signaling and has been shown to have a tumor suppressor function in ALK-positive ALCL [49].