IL1RN and nasopharyngeal carcinoma: In a small candidate gene study of Portuguese patients with NPC, homozygosity at allele A2 (two VNTR copies) of IL1RN was strongly associated with the non-keratinising form of NPC (OR = 4.08) when the allele frequency was compared with healthy controls [85]; the same polymorphism was associated, but not statistically significantly, with EBV seropositivity in a small sample of blood donors, highlighting the problem of investigating candidate gene associations in small studies [26].