RASSF1 and cancer: In order to validate RASSF1C as a modulator of cancer stemness with an alternative approach, we induced endogenous RASSF1C expression by epigenetic editing; where inactive Cas9 derivatives (dCas9) fused to a transcriptional activation domain (dCas9‐VP64) and single guide RNAs target the internal RASSF1 promoter (sgRASSF1C) to selectively promote expression of the RASSF1C transcript (see Fig EV4F, graphical abstract).