Recently, the proteomic panel was expanded to eight signature peptide biomarkers to screen for five molecularly defined IEI including adenosine deaminase (ADA) deficiency, dedicator of cytokinesis 8 (DOCK8) deficiency, X-Linked chronic granulomatous disease (XL-CGD), WAS, and XLA [60]. The gene discussed is DOCK8; the disease is Bruton-type agammaglobulinemia.