More than one-third of melanomas are 'pan-negative,' meaning they lack known mutations that can be targeted for treatment. But now researchers have identified two new genetic abnormalities in pan-negative melanomas. These abnormalities consist of the BRAF gene joined with another gene (PAPSS1 or TRIM24), and so are called BRAF fusions. The new study showed that about 8% of pan-negative melanomas have BRAF fusions. Next, the researchers grew melanoma cells with these BRAF fusions in the lab and tested known targeted treatments on them. While these cultured cells were not sensitive to the BRAF inhibitor vemurafenib, they were sensitive to the MEK inhibitor trametinib, suggesting that MEK inhibitors could be used to target melanomas with these BRAF fusions.