Herein, using a strict, direct xenograft tumor system and limiting dilutions of sorted human pancreatic cancer cells injected into NOD/SCID mice, we demonstrate that cell populations enriched for high ALDH activity alone fulfill the major criteria of a CSC and efficiently recapitulate the phenotype of the original tumor independent of CD133 cell surface expression. The gene discussed is LDHA; the disease is familial pancreatic carcinoma.