The TGF-β2 was purchased from Humanzyme (Chicago, IL, USA). Sorbinil ([4S]-6-Fluoro-2,3-dihydro-spiro[4H-1-benzopyran-4,4′-imidazolidine]-2′,5′-dione) was generously provided by Pfizer Central Research (Groton, CT, USA). Control small-interfering RNA (siRNA) and AKR1B1 siRNA (siAR) were obtained from Qiagen (Valencia, CA, USA). Human lens epithelial (HLE B3) cells were obtained from Usha Andley (Washington University, St. Louis, MO, USA), and cultured in complete Dulbecco's modified Eagle's medium (DMEM) supplemented with 1 g/L glucose, 4 mM L-glutamine, 20% (vol/vol) fetal bovine serum, 100 units/mL penicillin, and 100 μg/mL streptomycin. Cells were maintained in a humidified incubator containing 5% carbon dioxide at 37°C.