REPS2 and colorectal carcinoma: Consistent with their regulation by DKK-1, the RNA and protein expression of ALDH1A1, AKR1C3 and REPS2 was higher in CRC tumors containing nuclear DKK-1 than in those that lacked it (Fig. 5A) and it was associated with the presence of nuclear DKK-1 (Fig. 5B and C).