Antiviral proteins

Am I the last person to hear about antiviral proteins in cells? I know, I know, I read the Harvard magazine for once, science section. Anyway, they seem to have discovered that there are cellular proteins which are versatile and good at fighting viruses, and it's possible to treat cells with the proteins. It boggles my mind that we wouldn't have known this stuff already, but if it's really that new, it is very good news!
This reminds me that I should probably get myself a subscription to scientific news of some sort. Maybe I'd have a better idea of what is and is not medically viable. Or I could just ask my roommate who studies immunology...