For melanoma staging, we used Breslow thickness as our criteria for evaluating Apaf-1 expression: ⩽0.75 mm, low risk; 0.76–1.5 mm, intermediate risk; 1.51–4.0 mm, high risk; >4.0 mm, very high risk (Marghoob et al, 2000). The gene discussed is APAF1; the disease is melanoma.