ATF4 and Alzheimer disease: To further characterize these samples, we investigated the expression of the main GDF15 transcription factors, such as ATF4, ATF3, DDIT3 and TP53, which for instance are also strongly implicated in AD (Hooper et al., 2007; Baleriola et al., 2014; Zhu et al., 2014; Wei et al., 2015).