Bardet–Biedl syndrome (BBS) proteins and the cytoplasmic dynein light chain, Tctex-1, inhibit and enhance actin polymerization, respectively 6, 39 (Figure 2), but because these studies use either inhibitors of RhoA or the actin polymerization inhibitor, cytochalasin D, indirect effects cannot be excluded. This evidence concerns the gene RHOA and Bardet-Biedl syndrome.