Polycystin‐2 (PC‐2), a protein encoded by PKD2 and involved in autosomal dominant polycystic kidney disease (ADPKD), is a non‐selective cationic channel recently implicated in the function of primary cilia. We recently constructed a new animal model in the form of a transgenic mouse with a BAC‐containing human PKD2 inserted in its genome. Two transgenic mouse lines overexpressing human PKD2 showed mitotic instability. Fibroblasts from these transgenic mouse lines have abnormal chromosomal numbers. These lines also have supernumerary centrosomes. PC‐2 overexpression is associated with mitotic instability and centrosome overduplication. PC‐2 therefore seems to play a role in centrosome duplication, and this hypothesis is being evaluated in other models.