SPP1 and dysplasia: We validated OPN/SPP1 overexpression in an independent cohort of 107 EAC samples using real-time RT-PCR (Figure S1) and found significantly higher expression of OPN/SPP1 in all stages of EAC compared with Barrett's metaplasia (BE) and dysplasia (Figure 1B; p < 0.01 for stage I EAC and p < 0.0001 for all other stages).