CushingAcromegalyStudy: PLOS One Revised Version

This version was the revised version based on the reviews from PLOS One. The reviewer comments are grouped into issues #39 #40 #41 #42 #43 #44 #45

The major change in this release is the switch to an age-adjusted model for transcript abundance. We grouped subjects into two groups, under 60 or 60 and above and then corrected based on that grouping. This affected several q-values. We also observed that older subjects had lower IGF-1 levels and lower magnitude transcriptional changes. This was addressed in issue #40