MAPK1 and metastatic melanoma: We also found that BRAF class 1 mutations (20.3% vs. 5.8%) were more frequent in metastatic melanomas, while SPRED1 inactivation (3.9% vs. 19.8%), SF3B1 mutations (1.6% vs. 9.3%), and amplifications of CRKL (6.3% vs. 17.4%) and MAPK1 (1.6% vs. 11.6%) were more frequent in primary samples (Fig. 7E and Additional file 2: Fig. S15).