FBXO31 is the component of some SCF (SKP1-cullin-F-box) protein ligase complex that plays a central role in G1 arrest following DNA damage. FBXO31 specifically recognizes phosphorylated cyclin-D1 (CCND1), promoting its ubiquitination and degradation by the proteasome, resulting in G1 arrest. FBXO31 may act as a tumor suppressor.