SPP1 and breast carcinoma: Osteopontin, secreted by breast cancer cells, reprograms fibroblasts into a proinflammatory state, inducing Epithelial Mesenchimal Transition (EMT) in cancer cells via CXCL12 secretion (Singer et al., 2008; Liubomirski et al., 2019; Nurmik et al., 2020).