MED21 and metastatic melanoma: CYT-high metastatic melanomas had recurrent copy number amplifications in loci 1p12 (NOTCH2), 1q44 (OR2M4), 7q36.1 (KCNH2), 11q13.3 (FGF3/4), 12p11.23 (MED21) and 12q13.3 (R3HDM2) and deletions in 1p22.1 (RHOC, NRAS), 9p21.3 (CDKN2B), 10q23.2 (miR346), 11q23.3 (ATM, CHEK1, ETS1) and 15q15.3 (CASC4).