apo- vs en-

apo-

prefix
  • away from, or separate 

  • the apoprotein form of the protein 

  • derived from, or related to 

  • without, or lacking 

en-

prefix
  • on, onto 

  • an intensifier 

  • caused 

  • in, into 

  • covered 

How often have the words apo- and en- occurred in a corpus of books? (source: Google Ngram Viewer )