UGT1A1 and colorectal carcinoma: Variations in the UGT1A1 gene, particularly UGT1A1*28 and UGT1A1*6, are associated with decreased UGT1A1 activity [8], leading to the accumulation of SN-38 and an increased risk of adverse reactions and therapeutic effects in patients with advanced CRC undergoing irinotecan-based chemotherapy [10,22].