PKP1 and cancer: In support of these conclusions, RNASeq results showed that additional mesenchymal markers, such as Thy1, Snail, Meox1 or Fn1 were clearly down-regulated in SIX1/RAS tumors, while the cancer stem cell marker Prom1 (also known as CD133) and markers of epithelial or other cell types such as Ocln, Cldn1, Pkp1, were clearly induced in these tumors (Supplementary Fig. S7).