Figure 3  Heatmap of gene dosage at chromosome region 9p21 by Breslow thickness. Gene dosage ratios are shown for 18 tumors with Breslow thickness <2 mm (above), 30 tumors with Breslow thickness 2–4 mm (middle) and 27 tumors of thickness >4 mm. Blue coloration indicates reduced gene dosage, red coloration indicates increased gene dosage.