3.1 Survey of Studies

Microarray studies were obtained from two repositories, Gene Expression Omnibus (GEO, (EDGAR; DOMRACHEV; LASH, 2002) and ArrayExpress (KOLESNIKOV et al., 2015) To study the behaviour of the immune system, we used data from whole blood (whole blood) and PBMC (peripheral blood mononuclear cells), from healthy individuals of different ages. The inclusion criteria for a study to be selected were that there were at least 10 healthy/control samples, the presence of age information for each sample, availability of raw data and information on the sequence of the probes of the platform used.