The most common genetic abnormality in Japanese patients with melanoma occurs in the v-Raf murine sarcoma viral oncogene homolog B (BRAF) gene [7] (~30% of Japanese patients with melanoma); abnormalities are also observed in the KIT proto-oncogene, receptor tyrosine kinase (KIT) gene [7], and neuroblastoma RAS viral (v-ras) oncogene homolog (NRAS) gene [8]. The gene discussed is NRAS; the disease is melanoma.