ALDH1A1 and cancer: We found that CSCs expressed high levels of tumor stemness genes (PROM1, CD24, CD47, ANPEP, ALDH1A1, OLFM4, and SOX9), and demonstrated a high cancer stemness score (Figure S2A,B, Supporting Information), along with activation of the cancer driver genes EGFR and ERBB2 (Figure 2D).