Although you could set your Mutant City Blues series in a fictional metropolis, as you see in certain comic books, we instead recommend placing it in an actual city you and your players are very familiar with.
Doing so reinforces the game’s sense of social realism, underlining the idea that this is the real world after ten years of adjustment to widespread super powers. With that in mind, the setting chapter is presented not as a conventional gazetteer, but as a series of people, organizations and institutions to slot into the city of your choice. Entries for locations begin with suggestions on which sorts of neighborhoods to place them in.
Your existing knowledge about the laws, geography, police organisation and social background also gives you less to learn and makes it much easier to get into the game.