CD8A and inborn error of immunity: The KEGG pathway analysis revealed that the DEGs were primarily enriched in pathways related to cytokine − cytokine receptor interaction (19 genes, such as CXCL2, TNFRSF13, CD27), TCR signaling pathway (14 genes, such as ZAP70, CD8A), and Primary immunodeficiency (10 genes, such as ZAP70, TNFRSF13B) (Fig. 2b).