ARL3 and breast fibrocystic disease: Lack of Arl3 (Schrick et al., 2006) or ARL3-dependent lipidated proteins, Inpp5e and Nphp3 in developmental cko models (Wright et al., 2011; Humbert et al., 2012) or Cystin-1 mutants (Ricker et al., 2000; Hou et al., 2002; Omori et al., 2006), causes fibrocystic disease.