BRAF mutations, which are found in about half of melanomas, are far less common amongst Irish people, suggests a study presented at the American Association for Cancer Research's annual meeting. The researchers compared the melanomas of people in Ireland and Belgium and found that BRAF mutations occurred in only 21% of the former compared to the more typical 52% of the latter. This could be due to other genetic differences between the two countries. First, Irish patients had more NRAS mutations (21% vs 13%), which do not occur in melanomas with BRAF mutations. Second, 12% percent of the Irish patients had c-MET mutations, which are rare in melanomas, while none of the Belgian patients did. This work shows that treatments should be targeted to reflect genetic differences among populations.