Importantly, however, Bielaszewska et al. reported that stx2a-positive ST21 strains do not substantially differ in their association with HUS from stx2a-harbouring ST29 strains, and they therefore concluded that the possession of stx2a rather than the ST of the strain is a predictor for HUS development in O26 infection [21]. The gene discussed is STX2; the disease is infection.