[rotskoff]

In the chemistry / molecular biology community, that is definitely part of the role played by a journal like Cell. It is considered a very prestigious journal and tends to publish only what the editors and reviewers perceive to be very important findings. Of course, we (scientists) are imperfect reviewers and sometimes don't see the value in great work and likewise sometimes imagine greatness in mediocre work. Editors also feel pressure to select work that they believe will be rapidly and frequently cited---as the number of citations per paper in the first two years after publication affects the impact factor of the journal.

Unlike math and physics, many disciplines have only recently adopted preprint servers (like bioRxiv) and there's still some bias against posting preprints within the community.