Several clusters had the features of stem cells, including cancer stem cells (CSCs) (cluster0; CLDN10-AS1, TOX3, and PROM1), mesenchymal stem cells (MSCs) (cluster 3; ADAMTS2, LAMA2, and ABI3BP), vascular stem cells (VSCs) (cluster 7; RRM2, EXO1, and SKA3), and endothelial cell/submandibular gland stem cells (cluster 12; FLT1, PCDH17, and VWF) [39]. The gene discussed is RRM2; the disease is cancer.