It's the end of 2012, and that means it's time to take a look back at the year in retrospect. We'll be reading through the naughty and nice lists (we've already checked them twice), counting down the 25 best-performing stocks and the 25 worst-performing stocks in the health care sector this year.

In this segment, Motley Fool health care analysts Brenton Flynn and Max Macaluso take a look at No. 20 on the nice list, XOMA (NASDAQ:XOMA), and how this company left investors with more than a little something extra in their stockings this year.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.