TMEFF2 and Alzheimer disease: Moreover, the Wnt signaling pathway and TMEFF2 methylation exhibit opposite activation states or effects in CRC and AD, while other factors such as Psen1, microRNA, methylation, mitochondrial oxidative stress, and blood-brain barrier ATP-binding cassette transporter proteins also play a regulatory role in both diseases (Tremolizzo et al., 2006; Thinnes, 2012; Aliev et al., 2013; Manandhar et al., 2020; Masood et al., 2020; Ghafouri-Fard et al., 2021; Kadkhoda et al., 2022).