In mycosis fungoides (MF), for example, CD30 positivity is much less than in ALCL, with one group reporting median epidermal staining of 14% in non-transformed cases, with higher expression levels in more advanced stages and large-cell transformation.28 It is a matter of debate whether CD30 expression levels permit stratification of expected responses to anti-CD30 therapies. The gene discussed is TNFRSF8; the disease is mycosis fungoides.