"It's not a metaphor for AIDS, Andy S, but rather for age. At least, if you take what Cronenberg has said about the film since. Thankfully most of us don't (usually) lose our fingernails, ears, and eventually metamorphose into a hideous human fly. There's the scene when Goldblum loses his first fingernail, and he says 'What's happening to me, am I dying?' It's one of the most chilling moments of the film. The film deals very directly with the finite nature of our existence and it's this, as much as the gore, that makes it difficult to watch."