Importantly, we found that samples from subjects with Tangier disease do not contain preβ1-HDLs when using our one-dimensional native PAGE gel (Fig. 6a), however, when we examined the sample on our two-dimensional gel system, we did find a preβ1-HDL-like spot (Fig. 6b), probably consisting in preβ1-HDL-like/lipid-free apoA-I aggregates (Fig. 6c). This evidence concerns the gene APOA1 and Tangier disease.