ARL6IP5 and diabetes mellitus: Studies have associated the Hp2-2 phenotype with increased morbidity from cardiovascular disease, diabetes, HIV infection, and other conditions—perhaps because concentrations of Hp2-2 are lower, Hp2-2 is less able than Hp1-1 to penetrate extravascular spaces, and Hp2-2 is less able to prevent oxidative damage or immune activation than the other phenotypes [7].