REG1B and inflammatory bowel disease: We found 84 differentially expressed genes in active extensive UC compared to non-IBD controls, and 20 in inactive extensive UC, with an overlap of 5 genes (REG1B, REG1A, MUC4, GRAMD2, and CASP10; Figure 1, Table 3, Supplementary Figure S2B, and Supplementary Table S2).