Figure 1

Ratings of bitter intensity by subjects with one of three TAS2R38 diplotypes. Subjects were grouped by genetic variant, either AVI (alanine, valine, isoleucine) or PAV (proline, alanine, valine), AVI (AVI/AVI, n = 146) are shown in in solid black; AVI/PAV (n = 265) in medium grey, and PAV (PAV/PAV; n = 108) light grey). The observations were grouped into bins by intensity rating, and are expressed as the percentage of subjects. For example, subjects to the left rated PTC as not intense at all, and were more likely to have the AVI/AVI genotype.