The tumour phenotype (Figure 1d) was comparable between the cohorts, being predominantly monocyte/macrophage tumours (Mac1+F4/80+) with a small proportion of T-cell tumours (Thy1+CD3+ and variable CD4 and CD8 expression), as previously reported for MYC10 mice.32 Tumours of all genotypes were transplantable in C57BL/6 recipients (n=9–12 independent tumours). The gene discussed is CD4; the disease is neoplasm.