For the sake of completeness, we need to mention that it is virtually contradicting that oleuropein in breast cancer cells decreases the SIRT1 level and in gastric adenocarcinoma cells it increases the KRAS while oleacein in 501Mel cells decreases the KRAS and mTOR expression but all mechanisms lead to chemopreventive effects [91,92,109]. Here, KRAS is linked to gastric adenocarcinoma.