ABCB1 and gastrointestinal disease: In reverse, Figure 1 shows proportions of cases across the patient subsets based on the increasing load of variant alleles across the four ABCB1 polymorphisms: raw proportions, weighted proportions based on balanced data and estimated probabilities from a multivariable logistic model for balanced data with additional adjustment for age, history of cancer, gastrointestinal diseases and use of CYP2J2 inhibitors – there is no obvious trend in the proportion of cases (bleeding) with increasing number of variant alleles.