text: Yo, check it out, here's the deal,
  When it comes to testin' drugs, it's a big ordeal.
  Especially when the therapy's a human protein,
  It's hard to find the right animal to intervene.
  
  See, these molecules are specific, they ain't like the rest,
  They target humans, puttin' us to the test.
  Rodents and dogs, the usual toxicology species,
  Might not respond to the human protein pieces.
  
  Or worse, they might get all immunogenic,
  Formin' antibodies, that ain't strategic.
  It messes up the studies, can't go on for long,
  Them neutralizing antibodies, they're just too strong.
  
  So, you see, testin' biotherapeutics ain't a breeze,
  Gotta find the right animal species, please.
  Preclinical safety, it's a real challenge, you know,
  Picking the right critters, watchin' 'em grow.