ALDH1A1 and colorectal carcinoma: Follow-up data showed that OS time was significantly shorter in CRC patients with positive expression of ALDH1 (47.1 ± 22.4 months) compared with those with ALDH1-negative (64.3 ± 21.9 months; log-rank = 16.908, P < 0.001; Fig. 2a).