Next, using a univariate general linear model, where the dependent variable was the RNA expression levels and the independent variables were the specific RNA variants (circAPP (hsa_circ_0007556) and APP mRNA) and the presence of disease (AD or control), it was observed that the expression of the two transcripts together in AD cases was 37.75% lower (p-values < 0.05) with respect to the controls. Here, APP is linked to Alzheimer disease.