If your research is concerned with the expressed physiological functions of genes, you might want to consider joining the Physiological Genomics Group. If your work serves to translate research discoveries from the bench to the bedside, you might want to sign up for the Translational Research Group. There is no need to resign from your section to join a group.
Groups tend to be cross disciplinary, tending to cross the boundaries of multiple sections.
Each group has the ability to program sessions at the annual meeting.