Alterations in the ratio of cd4: cd8 lymphocytes are associated with risk of hiv infection progressing to aids, of autoimmune diseases, and of progression of some cancers. in searching for predictors of these effects in normal individuals, researchers have found a region of the human genome with 2 markers that are associated with the cd4: cd8 ratio. what does this indicate for the general population? a) one of the markers must be in a gene that affects the cd4: cd8 ratio. b) autoimmune diseases such as type 1 diabetes are caused by a gene in this region. c) this is the only region of the genome that affects the cd4: cd8 ratio. d) the cd4: cd8 ratio is affected entirely by the environment. e) the markers are in linkage disequilibrium with a mutation that affects the cd4: cd8 ratio.