RhoBTB2 is one of the three members of the RhoBTB family. All RhoBTB proteins are characterized by a GTPase domain followed by a proline-rich region, a tandem of two BTB domains and a C-terminal putative RING finger domain. RHOBTB2 is a putative tumour suppressor gene. Expression of RHOBTB2 has been found decreased in breast, lung and bladder tumors, head and neck squamous cell carcinoma and osteosarcoma. Decreased expression is often the result of promoter methylation. Mutations are uncommon. The role of RhoBTB2 in tumorigenesis is unknown but may be related to its function as a component of Cullin 3-dependent ubiquitin ligase complexes regulating the cell cycle and apoptosis....