ARID2 and melanoma: All 13 metastases carried an activating missense BRAFV600R mutation (c.1798_1799delGTinAG), as well as mutations in the melanoma driver genes PTENA43T and MAP2K1G128S (the latter has not been previously reported in the COSMIC database27), and a splice-site variant in ARID2, all of which were truncal across all metastases.