Varney et al. studied 1,771 type 1 diabetes multiplex families, analyzing them by the affected family-based control method [26], and found that DPA1*0201 has a protective effect on the development of type 1 diabetes (adjusted P = 5×10−4, OR 0.7) [22]. The gene discussed is HLA-DPA1; the disease is type 1 diabetes mellitus.