Local development would greatly affect the medical field. For instance, just look at the surgical textbooks. For the first five editions, the editors were mostly military doctors. Starting from the sixth edition and onwards, doctors from Beijing and Shanghai became more common as the editors. The more recent the edition, the more doctors from Beijing and Shanghai there would be. The editors of such surgical textbooks could be called some of the best Chinese doctors in their respective fields. Since the best doctors were concentrated so densely in only two cities, it wasn't strange at all for patients to also gather together in only those two cities. This caused all sorts of difficulties for everyone. It became more difficult to get treated, and it also became harder to work as a doctor! Such problems would then explode on the doctors working on the frontlines to treat everyone!