Additionally, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with these key genes included primary immunodeficiency, intestinal immune network for IgA production, renin-angiotensin system, cytokine-cytokine receptor interaction, and butanoate metabolism (Figure 8E), while the q < 0.05 cut highlight the first two. This evidence concerns the gene REN and inborn error of immunity.