Neanderthal genomes in modern humans

[Marble]

My questions are inspired by this thread.

I would would like to know what neanderthal genomes do in modern humans, what they contribute.
I read somewhere that those genomes help the body fighting diseases, but I cannot remeber any more where I read about this.
Anyway, is this true?
And if it is, could it be one of the reasons that AIDS is such a problem in sub-Saharan Africa because the people there do not have neanderthal genomes?

Sub-Saharan Africa is more heavily affected by HIV and AIDS than any other region of the world.

source

 

[cablescavenger]

My questions are inspired by this thread.

I would would like to know what neanderthal genomes do in modern humans, what they contribute.
I read somewhere that those genomes help the body fighting diseases, but I cannot remeber any more where I read about this.
Anyway, is this true?
And if it is, could it be one of the reasons that AIDS is such a problem in sub-Saharan Africa because the people there do not have neanderthal genomes?

source

I saw something a couple of years back suggesting interbreeding was common, and if memory serves me right I think it suggested red hair was a neanderthal trait.

 

[tree]

I read an article a few years ago that talked about a genetic study of Homo sapein's skeletons from around the time that we coexisted with neanderthals and it suggested that inter-breeding was common and there were several instances of neanderthal genes being found in humans. They said that modern humans however had almost no genetic information passed on from neanderthal cross breeding and that the lineages that might have resulted from the interbreeding must have died out.