PROM1 and cancer: Even though nuclear H3K27me3 levels were not significantly affected by inhibitor treatments (Figure 4A), enrichment of this mark was reduced by both drugs at genes not expressed in fibroblasts such as PROM1 (a cancer stem cell marker), SCG3 (expressed in brain tissue), and RDH16 (expressed in liver tissue) (Figure 4B), indicating efficient inhibition of the histone methylases EZH1/2.