title: Removing rows based on column in another dataframe
body: <p>Is there a way to remove rows from a dataframe, based on the column of another dataframe? </p>
  
  <p>For example, Dataframe 1: </p>
  
  <pre><code>        Gene CHROM    POS REF ALT N_INFORMATIVE     Test       Beta       SE
  AAA     1  15211   T   G          1481  1:15211 -0.0599805 0.112445
  LLL     1 762061   T   A          1481 1:762061  0.2144100 0.427085
  CCC     1 762109   C   T          1481 1:762109  0.2847510 0.204255
  DDD     1 762273   G   A          1481 1:762273  0.0443946 0.119924
  </code></pre>
  
  <p>Dataframe 2 (only 1 column): </p>
  
  <pre><code>Genes
  AAA
  BBB
  CCC
  DDD
  EEE
  FFF
  </code></pre>
  
  <p>In this situtation, I want to scan Dataframe 1, column 1 for any matches to Dataframe 2, and remove matching rows. </p>
  
  <p>They need to be an exact match, and the result would look like this: </p>
  
  <pre><code>        Gene CHROM    POS REF ALT N_INFORMATIVE     Test       Beta       SE
  LLL     1 762061   T   A          1481 1:762061  0.2144100 0.427085
  </code></pre>
  
  <p>I've tried variations of this, but it hasn't worked: </p>
  
  <pre><code>NewDataframe &lt;-!(Dataframe1$Gene==Dataframe2$Genes)
  </code></pre>
  
  <p>Thanks for reading.</p>