-CD44 and ALDH are the most specific biomarkers to detect and isolate tumorigenic and chemoresistant gastric CSCs in noncardia gastric carcinomas. -Tumorigenic and chemoresistant gastric CSCs co-express EPCAM, CD133, CD166, CD44, and ALDH.-ALDH is the most specific biomarker for CSC enrichment before CD44 in both diffuse- and intestinal-type noncardia gastric carcinomas. The gene discussed is CD44; the disease is gastric carcinoma.