Nielsen LB, et al. - The utility of an immunohistochemical (IHC) analysis underwent a comparative assessment with a frequently used mutation detection analysis in malignant melanoma and corresponding metastases. Researchers also inspected the extent of intra- and inter-tumour heterogeneity of BRAF V600E in primary tumours and their corresponding metastases. IHC analysis could be safely used as a BRAF pre-therapy screening tool. No further investigation was required when staining was positive. However, negative stains warranted additional tests for the detection of other BRAF mutations. Primary melanoma tissues displayed similar safety as the usage of metastatic tissue for the detection of BRAF V600E, since BRAF inter-tumour heterogeneity was extremely rare. The time between diagnosis of a primary tumour and diagnosis of the corresponding metastasis did not raise the risk of inter-tumour heterogeneity