Shabani F, et al. - Researchers systematically reviewed the available data on the pro- and anti-tumorigenic functions of calprotectin (S100A8/S100A9), a heterodimeric EF-hand Ca²⁺ binding protein, and its relation to inflammation. They found the presence of elevated levels of S100A8/S100A9 in inflammation, neoplastic tumor cells and various human cancers. As per recent data, sites of infection, chronic irritation, and inflammation give rise to many cancers. Regardless of the source of the aforementioned protein (extracellular or intracellular), different outcomes in inflammation, malignancy and apoptosis have been observed. These data suggest that anti-inflammatory therapeutic agents and anti-tumorigenic functions of calprotectin can lead to control cancer development.