I'm sure any beekeeper can tell you that a queen bee is just a worker that has been fed royal jelly, They wanted to study the process in more detail, because the principle is thought to work in other animals, including humans, and they were also trying to work out how to make 'clean' queens in an attempt to help repair the damage to the honey industry with what has become affected by something known as Colony Collapse disorder. They achieved the same results as royal jelly when they switched of a gene Dnmt3, which showed demetylization of DNA led to the development of certain traits.
Studies continue, but in humans things like obesity,infertility, longevity, and brain disorders, are thought to be affected by the chemical effects on genes