Whilst the median level of C3b/iC3b deposition for both patient populations remained approximately the same, there was increased variation in C3b/iC3b deposition on the bacterial cell surface when opsonised with serum from HIV individuals, which may perhaps be accounted for by differences in opsonising ability as HIV progresses towards AIDS (Acquired Immune Deficiency Syndrome). The gene discussed is C3; the disease is AIDS.