Abstract
Secreted Phosphoprotein 1 (SPP1), also known as Osteopontin (OPN), is a phosphorylated glycoprotein that plays a crucial role in regulating various cellular functions and immune responses. Recent studies have highlighted SPP1's involvement in key physiological processes, including cell migration, proliferation, differentiation, and its significant impact on immune regulation and inflammatory responses. In the context of cancer, SPP1 is closely associated with tumor progression and prognosis. It contributes to tumorigenesis by promoting the formation of the tumor microenvironment (TME), influencing the behavior of tumor-associated cells, and enhancing tumor cell invasiveness and immune evasion. This review aims to provide a comprehensive analysis of SPP1's role in the development and progression of various cancers, highlighting its potential as a therapeutic target and biomarker for cancer management.