Fill In the Blanks

So a virus is something that you can’t see by normal light microscopy, you need very advanced techniques for electron microscopy to see it, but that virus is not able to reproduce itself without a host and us as human beings are made up of lots of different cell types and we are interested in understanding at the molecular level how that virus infects the liver and why does it infect the liver and it doesn’t infect the heart or it doesn’t infect other tissues ?