Contrarily, several studies noted that TLs of the MCI patients (Zekry et al., 2010; Hochstrasser et al., 2012) or AD patients (Takata et al., 2012; Tedone et al., 2015) did not differ from the controls, but were shorter in ApoE4 homozygous AD patients (Takata et al., 2012). This evidence concerns the gene APOE and Alzheimer disease.