Notwithstanding the strong and uniform CD30 expression on HL and ALCL cells, it was not apparent that a minimal threshold of CD30 was required for tumour response in the pivotal studies of brentuximab vedotin for these lymphomas (Pro et al, 2012, 2013; Younes et al, 2012; Jacobsen et al, 2015). This evidence concerns the gene TNFRSF8 and lymphoma.