In addition, gene expression of aldo-keto reductase family 1 member B10 (AKR1B10), which catalyzes the reaction of retinal to retinol, was elevated in NASH patients compared to healthy subjects and NAFL patients, suggesting that retinal, the substrate of retinoic acid, is decreased (Figure 3 and Figure 4) [35]. This evidence concerns the gene AKR1B10 and non-alcoholic fatty liver.