This hypothesis was based on (i) the chromosomal locations of PGLYRPs: PGLYRP2 is located in the IBD susceptibility locus 19p13 [44]–[46] and PGLYRP3 and PGLYRP4 are located at 151.5 Mb on chromosome 1 near the 151.79 Mb IBD locus [9]; (ii) our data showing a role for PGLYRPs in experimental UC and other inflammatory diseases in mice [37]–[41]; and (iii) our data showing the effects of PGLYRPs on microbiome [37]. This evidence concerns the gene PGLYRP4 and inflammatory bowel disease.