Nucleolin is a ubiquitously expressed 100 kD nuclear and nucleolar protein that contains RNA recognition motifs. Nucleoloin is the major nucleolar protein of eukaryotic cells in growth phase associated with intranucleolar chromatin and pre-ribosomal particles. This protein induces chromatin de-condensation by binding to histone H1 and plays a role in pre-rRNA transcription and ribosome assembly. Nucleolin exhibits self-cleaving, DNA helicase, RNA helicase and DNA-dependent ATPase activities; activity can be upregulated in response to ERK signaling, c-Myc expression, and genotoxic stress (UV radiation). This protein is modified by phosphorylation (Thr76/Thr84). This protein interacts with phosphatase 1delta, hepatitis C virus NS5B, part of B-cell specific transcription factor complex with LR1, and DNA Topoisomerase I. The 10C7 monoclonal antibody recognizes human phosphorylated nucleolin (Thr76/Thr84) and has been shown to be useful for Western blotting.