p97, also known as Valosin-Containing Protein (VCP), is a widely expressed intracellular ATPase involved in various cellular processes, including protein degradation, membrane remodeling, and cellular stress responses. It forms hexameric structures with multiple family members and primarily localizes in the cytoplasm and nucleus. Through interactions with different cofactors and substrates, p97 regulates signaling pathways of the ubiquitin-proteasome system and non-ubiquitin pathways. Its expression is regulated by cell type and environmental stress, and mutations often lead to neurodegenerative diseases and muscle disorders.