STX2 and Behcet disease: When comparing patients with BD and non-bloody stool, univariate logistic regression revealed statistically significant differences for the same genes as identified using the χ2 and Fisher’s exact test (Tables 3 and 4), with the exception of lpfA. The genes were assembled into the following groups: adhesins (eae and espB_O157), secretion systems (espA, espF, espJ, etpD, nleA, nleB, nleB O157:H7, nleC, tccP), toxins (astA and toxB), and shigatoxins (stx1, stx2, stx2a, stx2c) and analyzed separately using forward stepwise logistic regression.