We used the KRAS mutant pancreatic cancer cell line PANC1 and the kidney cancer line SN12C, both of which have been shown to develop CSC-enriched 3D spheres.13, 14, 15, 16, 17, 18 Both pancreatic and kidney cancers are aggressive, develop metastatic tumors and have characteristic markers of CSCs with very few treatment options. The gene discussed is KRAS; the disease is kidney cancer.