1.   Beach Warren, for instance, went through numerous drugs and drug combinations, but most worked for only six months to a year before the virus developed resistance.

2.   All along, Grinberg has known that lurking in the background was the possibility of virus resistance to any new therapy.

3.   But the virus resistance could only create a superweed problem if viruses were preventing the spread of wild squash in nature.

4.   Finding a drug which can stave off virus resistance will be important to long term management of the disease, experts say.

5.   Finding a drug that can stave off virus resistance will be important to long-term management of the disease, experts say.

6.   Understanding virus resistance is especially important when putting together new drug combinations after the initial drug cocktail fails to wipe out all visible signs of the virus.