op">(</span><span class="va">gene_expression2</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/utils/head.html" class="external-link">head</a></span><span class="op">(</span><span class="va">gene_expression2</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   Genes  CT_1    CT_2  CT_3 LT20_1 LT20_2 LT20_3 LT15_1 LT15_2 LT15_3 LT12_1</span>
<span class="r-out co"><span class="r-pr">#&gt;</s