ALDH1A1 and colonic neoplasm: THF reduced the ALDH1-positive subpopulation from 2.4 to 1.6% in the MC-38 colon tumor and 1.1–0.2% in the 4T1 breast tumor (Fig. 9D and Fig. S5D) and the ALDH-expressing population from 2.2 to 0.2% and 0.8–0.2% in TDLN (Fig. 9E and Fig. S5D).