p54nrb, also known as NONO, is a multifunctional nuclear protein that plays a role in various nuclear processes, including transcriptional control, RNA splicing and editing, and DNA unwinding and pairing. It is involved in the nuclear retention of defective RNAs and RNA transport, and its disruption can lead to expressional changes of tumorigenic genes and decreased stress tolerance, resulting in increased cell death susceptibility in human tumor cells. Additionally, p54nrb is multiphosphorylated during mitosis and interacts with the mitotic regulator Pin1, suggesting its involvement in cell cycle regulation.