SPP1 and neoplasm: Based on these findings we examined in vivo whether Au@Ag nanoparticle treatments would lead to decreased expression of Spp1. Using western blot analysis, we quantified the intratumoural levels of Osteopontin as well as of the fibroblast markers alphaSMA and Vimentin in the Saline- and Au@Ag-treated 4T1 tumour samples (Fig. 5g) (in tumours obtained from animals in experiment shown on Fig. 2b–e).