Someone just emailed me a copy of an interesting press release. Some time back, a particular mutation known as CCR5delta32 was identified as conferring greatly increased resistance to HIV in individuals who had two copies of that particular gene (in geek terms, those are individuals homozygous for that particular allele). According to the press release, a group of researchers have discovered that this resistance to HIV comes with a price. The individuals who are homozygous for the CCR5delta32 allele do have greatly increased resistance to HIV, but they also have greatly decreased resistance to the West Nile Virus.
This is interesting (to me, anyway) for a number of different reasons.