sanctuary site /sangk′cho̅o̅·er′ē/ [L, sanctus, sacred, situs, location] , an area of the body that is poorly penetrated by pharmacological agents and therefore is a place in which tumor cells or infectious organisms can escape the effects of drug therapy. For example, because most drugs that are effective against the human immunodeficiency virus (HIV) do not cross the blood-brain barrier, the central nervous system provides an area in which HIV can avoid the effects of antiviral therapy and from which resistant virus can later emerge.
