title: Remove an entire column from a data.frame in R
body: <p>Does anyone know how to remove an entire column from a data.frame in R? For example if I am given this data.frame:</p>
  
  <pre><code>&gt; head(data)
     chr       genome region
  1 chr1 hg19_refGene    CDS
  2 chr1 hg19_refGene   exon
  3 chr1 hg19_refGene    CDS
  4 chr1 hg19_refGene   exon
  5 chr1 hg19_refGene    CDS
  6 chr1 hg19_refGene   exon
  </code></pre>
  
  <p>and I want to remove the 2nd column.</p>