In this study, the contribution of the p35 and p40 subunits as monomers (noted as IL-12p35 and IL-12p40) and heterodimers (noted as IL-12p70 or IL-12p35/p40) was analysed in the pathophysiology and progression of chronic spontaneous urticaria (CSU). The gene discussed is IL12A; the disease is chronic idiopathic urticaria.