IL9 and Menkes disease: Notably, saliva concentrations of a number of immune proteins were also increased in MD patients, compared to HC (IL-1β: p < 0.01; IL-6: p < 0.05; IL-8: p < 0.01; IL-9: p < 0.01; CCL-2: p < 0.001; RANTES: p < 0.05; TNFα: p < 0.05; and VEGF: p < 0.01) (Figure 5A).