title: Getting unique elements from two lists
body: <p>I have two data frames,</p>
  <pre><code>df1 &lt;- data.frame(gene = c(&quot;Gen1&quot;, &quot;Gen2&quot;, &quot;Gen4&quot;))
  
  df2 &lt;- data.frame(gene = c(&quot;Gen1&quot;, &quot;Gen2&quot;, &quot;Gen5&quot;))
  </code></pre>
  <p>I would like to extract the unique elements of each list, so I end up with another two data frames</p>
  <pre><code>df3 &lt;- data.frame(gene = c(&quot;Gen4&quot;))
  
  df4 &lt;- data.frame(gene = c(&quot;Gen5&quot;))
  </code></pre>
  <p>Thanks in advance, Jose.</p>