In the context of gastrointestinal diseases, an integrative meta-analysis of 3 microarrays from patients with Crohn's disease identified ELAV-like RNA binding protein 1 (ELAVL1) and APP as the most significantly, upregulated and downregulated, respectively, in the blood of patients with Crohn's disease (Li et al., 2020). Here, APP is linked to Crohn disease.