Both primary cutaneous anaplastic large cell lymphoma (pcALCL) and MF are characterised by expression of cell-surface CD30 antigen; pcALCL is characterised by a high level of CD30 expression (≥75% of tumour cells) [4], whereas MF may express CD30 to a more variable degree (<1–100%) [5–8]. This evidence concerns the gene TNFRSF8 and mycosis fungoides.