Genes regulate proteins (determine which proteins are produced and when) and it is proteins that regulate all the cellular functions in our body
For example, Vancomycin works by interfering with a protein’s ability to repair damaged cell walls.  So when a healthy protein develops a leision in its cell wall, it produces a protein that fixes the hole.  Vancomycin interferes with the ability of the protein to do its job so that the leision becomes fatal for the bacteria that we want to kill.  That is, proteins control everything in our bodies.