Large-scale case-control association studies and familial linkage studies have confirmed the genetic contribution to NPC predisposition, by revealing multiple susceptibility loci of NPC, such as HLA genes [3–6], TNFRSF19 [5], MECOM [5], GABBR1 [3], XRCC3 [7], ITGA9 [4], TERT-CLPTM1L [8–10], and CIITA [8]. The gene discussed is CIITA; the disease is nasopharyngeal carcinoma.