PROM1 and mucoepidermoid carcinoma: Through an exhaustive permutation and combination of the four markers, as shown in Fig. 5, we found several combinations of markers had the potential to stratify the survival curves for MEC patients of the palate, including CD44/CD133, CD44/SOX2, CD133/SOX2, CD133/Nanog and CD44/CD133/SOX2, among which CD44/CD133/SOX2 having the strongest prognostic value.