SIX2 and cancer: Four primary cell populations were first identified using canonical cell markers: WT tumor cells (WT1, NCAM1, SIX1, SIX2, PAX2), cancer-associated fibroblasts (CAFs) (ACTA2, TAGLN, COL1A1, PDGFRB), endothelial cells (PECAM1, CLDN5, ENG, VWF) and immune cells.