These percentages are comparable with the original description of 12 of 15 cases (80%) being NRAS,37 and with 77% and 8% NRAS and BRAF, respectively, described in another cohort of 66 patients with CMN.40BRAF mutations as the first (or at least primary driver) hit as the cause of multiple CMN has only very recently been demonstrated,44 and has effectively confirmed previous reports of likely BRAF mosaicism in previous studies.40 The gene discussed is NRAS; the disease is congenital mesoblastic nephroma.