The expression of several apoptosis-related genes such as BAX (BCL2 Associated X Protein) and BAD (BCL2 Associated Agonist of Cell Death) and oxidative stress response genes such as SOD1 (Superoxide Dismutase 1, Soluble), GPX1 (Glutathione Peroxidase 1), GPX4 (Glutathione Peroxidase 4), PRDX1 (Peroxiredoxin 1), PRDX5 (Peroxiredoxin 5) were observed to be significantly upregulated in XLA patients compared to healthy subjects. The gene discussed is GPX1; the disease is Bruton-type agammaglobulinemia.