SPP1 and neoplasm: Recent studies have reported macrophages highly expressing SPP1. In gliomas, PTEN deficiency activated the YAP1 gene, which directly upregulated the expression of lysyl oxidase (LOX), a macrophage chemoattractant that activated YAP1 in the β1 integrin–PYK2 pathway in macrophages, which in turn secreted high amounts of SPP1, thereby maintaining glioma cell survival and stimulating angiogenesis within the tumor (36).