Further, after the knockdown of AKR1C1 in human breast cancer cells HCC1806, we found that the apoptosis signaling pathway was significantly upregulated (Figure 5K,L; Figure S5I and Table S5, Supporting Information) and the mean fluorescence intensity (MFI) of ROS was significantly increased (Figure 5M). The gene discussed is AKR1C1; the disease is breast cancer.