Supplementary Figure 1 from Preexisting &lt;i&gt;MEK1&lt;/i&gt; Exon 3 Mutations in &lt;sup&gt;&lt;i&gt;V600E/K&lt;/i&gt;&lt;/sup&gt;&lt;i&gt;BRAF&lt;/i&gt; Melanomas Do Not Confer Resistance to BRAF Inhibitors