The aldo-keto reductase AKR1B1, involved in glycerolipid metabolism and often overexpressed in human cancers and recently shown to promote breast cancer progression, showed a strong up-regulation in the third SV40-transformed stage (log2FC = 2.3), whereas it was downregulated in the immortalized stage (log2FC = −2.3) [36]. This evidence concerns the gene AKR1B1 and breast cancer.