That's true. Some rankings like the one from Nature I mentioned do include institutes. As a result, places like Wellcome Sanger in Cambridge or Helmholtz in Ger

That's true. Some rankings like the one from Nature I mentioned do include institutes. As a result, places like Wellcome Sanger in Cambridge or Helmholtz in Germany rank really well and above most leading universities in their field. As you say, these are not universities, but research institutes and therefore ignored by ARWU, US News and others.