SPP1 and neoplasm: Interestingly, the expression of Opn, which contributes to tumour growth via angiogenesis promotion22–26, apoptosis inhibition22,26–28, epithelial-mesenchymal transition (EMT) induction22,29,30, bone marrow-derived cell recruitment22,25,31, and cytotoxic CD8+ T cell suppression32, was significantly upregulated in the tumours of the HFD-fed PyMT mice (Fig. 1c).