BBS4 and Bardet-Biedl syndrome: Rather than using WT BBS4 gene replacement to rescue Bbs4KO olfactory cilia, we restored the cilia length in this study by reversing the aberrant distribution of PI(4,5)P2 and F-actin, 2 common factors that contribute to the pathogenesis of multiple BBS (Figure 2 and Figure 4, E and F).