Human VICs from calcifying valves, as well as VICs following 7-day OM-treatment exhibited an osteogenic phenotype, characterized by increased alizarin red (Figs. 1G and 1H) and alkaline phosphatase reactivity (Figs. 1I and 1J), and upregulation of calcification markers, OPN and RUNX2 (Figs. 1K and 1L). Here, SPP1 is linked to ocular melanoma.