"Doctor's Orders" is the side quest in Borderlands 2.
Having this quest active, but never collecting any Experiment Notes, allows for an exploit in The Preserve. Make it to the area of the Preserve where Bloodwing is head and head into the room with the numerous boxes. If you have not collected any of the Experiment notes, then you are very likely to find numerous Loot Midgets and Loaders. This is a great way to farm for gear - as of 9/13/13
Sidequest (Optional Mission)
How to start
Speak to Tannis
TURN IN: Tannis
Money and XP
Horrible, disgusting things happened at Wildlife Exploitation Preserve. Tannis is super-interested in them.
Tannis has all the information she needs on Slag experimentation. One can only hope she'll use it the information for non-horrifying purposes.