Since the identification of NOD2 mutation as the causative gene underlining BS in 2001 [3], more than 40 pathogenic mutations have been identified in the NOD2 gene concentrated on or close to the nucleotide-binding oligomerization domain (NOD)/nucleotide-binding and oligomerization (NACHT) subdomain interfaces [2, 4–6]. The gene discussed is NOD2; the disease is Bloom syndrome.