title: In R, get a subset of the data frame where the value in a column are contained in a list
body: <p>For instance, let's say I have a dataframe named <code>df</code> with a column <code>"ID"</code> of integers and I want to grab the subset of my dataframe in which the value in <code>"ID"</code> is in the vector <code>[123,198,204,245,87,91,921].</code></p>
  
  <p>What would the syntax for this be in R?</p>