Pc-ALCL shows a higher expression of the skin-homing chemokine receptor genes CCR10 and CCR8 and aberrant expression of genes implicated in apoptosis (TNFRSF8/CD30, TRAF1) and proliferation (IRF4/MUM1, PRKCQ) [94,103,135]. The gene discussed is IRF4; the disease is anaplastic large cell lymphoma.