ABSTRACT
The discovery of the human immunodeficiency virus (HIV)-1 coreceptor offers example that complex cellular determinants contribute to difficult interpretations of virus biology. Understanding virus-induced diseases, either HIV or non-HIV, is compounded by the complexities inherent to the virus, the host reaction, epidemiological considerations, study-system variables, and, indeed, virus superinfections of the primary viral disorder. It is apparent that HIV is neither uniquely confusing nor uniquely complex. The complexity of HIV is one that is inherent to all biological systems. Kaposi's sarcoma illustrates another case in which careful consideration of viral etiologies is important to understanding complex pathologies. The strong belief that herpes simplex virus (HSV)-2 accounted for cervical cancer despite difficulties in demonstrating viral DNA in cervical cancers led to the proposition of a "hit-and-run" hypothesis. Cervical cancer is highlighted by its strong epidemiological association with smoking, age, and multiple sexual partners.
