Another transcript that showed a stepwise differential expression in three cases (cases 4, 5, and 6) was SPP1. Lowest expression of SPP1 was observed in hyperplastic samples, with increasing expression from low-grade (0.79-fold, p = 0.76) to high-grade dysplasia (1.24-fold, p < 10-4) and highest expression seen in invasive carcinoma (1.6-fold, p < 10-5). Here, SPP1 is linked to invasive carcinoma.