Taking into account the fact that the minor T allele of IL1B −511 renders high IL-1β producer phenotype with more severe and prolonged inflammatory response [28–30], and that polymorphism at −1031 of the TNF gene has been associated with enhanced expression of this cytokine [31], with increased frequency of these genotypes observed in congenitally infected children compared to healthy controls, suggests that a strong inflammatory response may make the foetus more prone to CMV infection. The gene discussed is IL1B; the disease is cytomegalovirus infection.