One example of evidence of such modifiers was the report demonstrating that a 430C to T transition in MGC1203 gene (a pericentriolar protein CCDC28B that interacts with several Bardet–Biedl syndrome, BBS proteins) has an epistatic effect on BBS patients (Badano et al., 2006). This evidence concerns the gene BBS2 and Bardet-Biedl syndrome.