Other examples of phase 1 trials that have successfully been enriched for specific target patient populations include the hedgehog inhibitor GDC-0449 in patients with advanced basal cell carcinoma [14, 15] and the v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibitor PLX4032 in patients with malignant melanoma harboring V600E BRAF mutations [16]. Here, BRAF is linked to basal cell carcinoma.