PROM1 and cancer: In the present study, we showed that the combined use of vemurafenib + trametinib blocked the expression of OCT4, which also plays a role in the maintenance of normal somatic stem cells84; however, CSC markers such as NGFR, BMI1, CD133 and nestin were not downregulated in the vemurafenib + trametinib group (Figure 6B), although these highly malignant factors have been thought to be the cause of tumorigenicity and cancer recurrence14,74,81,85,86.