A post-marketing commitment for the approval of brentuximab vedotin + cyclophosphamide, doxorubicin, and prednisolone (CHP) in front-line sALCL or other CD30-expressing peripheral T-cell lymphomas is to develop a clinically validated in vitro diagnostic for CD30 expression to inform patient selection. This evidence concerns the gene TNFRSF8 and peripheral T-cell lymphoma, not otherwise specified.