We have fairly interesting (and complex) immune systems. One thing they are generally not that good a fighting is cancer, because the immune system is generally geared towards taking care of foreign things, viruses, bacteria and the like, and cancer is not foreign, it's the body itself failing to work properly. The part of the immune system that identifies contaminated cells, antibodies, don't see any contamination because it's just normal cells not working properly rather than contaminated cells. Still, these abnormal cells produce some proteins that normal cells don't, so researchers have been trying to use antibodies to identify those proteins. And now the kicker - there's a fair number of people who have been working on this for a while, but it appears some researchers from Seattle have found a useful antibody/drug combo, where a fairly lethal drug is attached to an antibody that targets the odd proteins that cancer cells produce. The antibody/drug complex is taken inside the cell, where the drug gets released and goes nato, destroying the cell. The antibody is acting as a targeted drug delivery system (surprise surprise, cancer drugs are generally fairly nasty things, toxic things designed to kill, better targeting means lower doses and putting less nasty shit into patients is a good thing®), all very elegant, so far, quite efficient and very cool. Then again, there's lots of cool stuff happening in cancer research these days.