Grey's Anatomy is oftentimes closer to a soap opera than a primetime network television show, which is made clear by the number of times the characters should have been fired from their jobs at Seattle Grace Hospital. In particular, Izzie Stevens, played by Katherine Heigl, broke eight rules during her time on the ABC medical drama series, which should have resulted in her being removed from the hospital. However, Grey's Anatomy is a fictional show in its own universe with its own set of rules, meaning that the penalty for breaking some regulations in the series isn't the same as in the real world.
