Holy moly XP... I remember those days.. The cold war was going on right? haha just kidding...
If you set it too 50% then ya thats fine.. If you left it where it was at 100% it would still be able to function fine.. This application takes a background to your OS functions.. So even if its using 100% the CPU could say oh I need more power to open this new page on IE or whatever browser you are using faster than you could count from 1 to 2 in your head.. Needless to say very fast within a millisecond.
Your second question.. This is all related to cancer... So for example I have been working on "Protein G" or your "antibiotic" a delivery system.. It would be just as important to be working on say "Biology Sample 1334A" that might be a plant from asia that may lead to something that cures cancer.. More importantly (what we are doing here) may lead to something, that leads to something, that leads to something, that leads to something, act, that cure cancer... Make sense? Don't be discouraged though! Even though we may be only working on a precursor to the cure for cancer, we are still non the less helping to find the cure for cancer!