The VL started a unique line of investigation looking for gene polymorphisms of the immune and inflammatory responses which could be biomarkers influencing the progression of HIV-1 infection, including mannose-binding lectin (MBL), IL6, IFNγ, IL-8, IL-10, TGFβ and FAS/FASL genes. Here, TGFB1 is linked to HIV-1 infection.