title: Superscript in brackets for my axis title
body: <p>I made a boxplot with <code>boxplot()</code> and I have a superscript in my y-lab labeling.
  It looks like this:
  <code>ylab = expression(paste("spleen volume cm"^3))</code></p>
  
  <p>Now I want the "cm3" with the superscript of "3" in brackets [cm^3]. </p>
  
  <p>I tried this:</p>
  
  <pre><code>ylab = expression("spleen volume " (paste("[cm"^3, "]")))
  </code></pre>
  
  <p>but unfortunately the whole thing is in () too, how can i remove these "()" around it? <a href="https://i.stack.imgur.com/9hud2.png" rel="nofollow noreferrer">here is how it looks like right now</a></p>
  
  <p>Unfortunately I am failing, can anyone help?</p>
  
  <p>Kind regards!</p>