BCL2 and melanoma: The resistance to apoptosis evidenced by the expression of BCL-2 and BCL-XL was clearly different between the three clusters: melanoma cells grouped in cluster 1 showed a higher expression of BCL-2 than melanocytes and also than melanoma cells grouped in clusters 2 and 3 (+150% versus adult melanocytes, P < 0.001; +150% versus cluster 2, P < 0.001; +900% versus cluster 3, P < 0.001) and BCL-XL (+38% versus adult melanocytes, P < 0.01; +57% versus cluster 2, P < 0.001; +38% versus cluster 3, P < 0.01) (Figure 8E).