To further exclude the potential side effects caused by the high concentration of epalrestat and to test the drug specificity, the colon cancer cell line SW480, which essentially does not express AKR1B1 according to the Cancer Cell Line Encyclopedia (CCLE) RNA-seq data (Additional file 1: Fig. S7c), was treated with the same concentration of epalrestat. Here, AKR1B1 is linked to cancer.