Overexpression of CD133 promotes the phosphorylation of Erk1/2 in human glioblastoma cells [36], but in our CD133-overexpressing HNSCCs, treatment of Erk1/2 inhibitor (U0126) caused only slight influence on CD133-overexpressing induced EMT (Figure 5F and data not shown). Here, PROM1 is linked to glioblastoma.