 In this study, we propose to utilize a novel bioinformatical approach the analysis of the shapes of Ig gene mutational lineage trees. This is the main innovative feature in our proposal, as it taps into parameters that have never before been measured or analyzed with respect to B lymphocytes in IBD. While the method is new, it has already been shown that graphical analysis of B cell lineage trees and mathematical quantification of tree properties provide novel insights into the mechanisms of normal and malignant B cell clonal evolution. A preliminary analysis of lineage trees from other autoimmune diseases shown below indicates that, given sufficient amounts of data, the method could elucidate changes in Ig gene diversification and selection in IBD patients. 