Major impact of the type of gastrointestinal decontamination on prognostic significance of NOD2/CARD15 variants. Differences were highly significant (P < .001) for patients receiving Gram-negative decontamination or no decontamination at all, but did not reach significance in patients with combined Gram-negative and Gram-positive decontamination. Numbers in parentheses indicate the number of patients analyzed for each type of gastrointestinal decontamination. (A) GvHD grade III/IV and type of decontamination (n = 289, 14 patients were excluded from analysis due to early death). (B) Overall TRM and type of decontamination (n = 303).