Of note, in keeping with the melanocytic origin of the lines, reverse-phase protein array (RPPA) profiling revealed robust expression of the melanocyte marker gp-100 (Supplementary Fig. 3) and other key uveal melanoma factors including quinone oxidoreductase-1 (NQO1)27 and DUSP4 (refs. 23,28; Supplementary Table 2). This evidence concerns the gene DUSP4 and uveal melanoma.