BBS increased luciferase activity by > 80-fold as compared to controls (mean activity 5.30 × 107 photons/s for controls vs. 4.27 × 109 photons/s for BBS) whereas Y15 decreased the activity by < 110-fold as compared to controls (mean activity 5.30 × 107 photons/s for controls vs. 4.78 × 105 photons/s for Y15). This evidence concerns the gene BBS2 and Bardet-Biedl syndrome.