The virulence of STEC depends on the presence of Shiga toxins 1 and/or 2 (stx1 or stx2 genes) which can be subdivided into subtypes (stx1a-1d and stx2a-2g). There are certain subtypes, specifically, Stx2a and Stx2d, which, in conjunction with the presence of the E. coli attachment and effacing (eae) gene, are associated with an increased risk of STEC-HUS [8]. The gene discussed is STX2; the disease is hemolytic-uremic syndrome.