Inhibitor, protease: An agent that can keep a protease from working and splitting a protein into peptides. Protease inhibitors are used in HIV/AIDS treatment. The protease inhibitors represented a major advance in treating HIV infection and AIDS. However, these drugs are not entirely without side effects. A lipodystrophy syndrome appears associated with the protease inhibitors. In this syndrome, the face, arms and legs become thin due to loss of subcutaneous fat. The skin becomes dry. The lips crack. Weight drops. Lawrence K. Altman in The New York Times observed that, "Veins stick out as cords, and although normal, may be mistaken for varicose veins. While fat disappears from some areas, it redistributes to build up in others. The back of the neck (takes on fat and) resembles a buffalo hump. Breasts enlarge. A woman may have to buy a bra that is two sizes larger than the last one. The abdomen swells producing a sometimes painful pot belly that is dubbed "a protease paunch." A woman may look pregnant when she is not. Exercise may not work it off." How the protease inhibitors induce this lipodystrophy syndrome is unknown. Another problem with the protease inhibitors is the development of strains of HIV that are resistant to these drugs, as was reported at the 12th World AIDS Conference in 1998 by a team led by Frederick M. Hecht at the University of California, San Francisco and workers from Switzerland.