TNF and leprosy: Zhang et al. (2009) identified by GWAS six genes associated with leprosy resistance/susceptibility, some of which have been replicated [6], [12], [13] including NOD2. Several genes involved in the pathogenesis of leprosy have been observed, such as PARK2/PACRG, LRRK2 and TNFSF15, participating in the regulation of host-cell apoptosis [12], [14], and also genes that participate in the formation and maintenance of granulomas, such as TNF, LTA and IFNG[15], [16], [17], [18].