To generate more rapid and robust models of melanoma, we combined Braf mutation with targeted deletion of the key tumor suppressor genes Pten or Trp53 – both commonly mutated in patients, and both known to synergize with BRAF-V600E in accelerated melanomagenesis in the mouse (Fig. 1B; refs. 5, 39, 40). Here, BRAF is linked to melanoma.