Of the seven genes that were overlapping between all gut functions (GUCY2C, EPCAM, MYO5B, PYY, SLC10A2, TNF, and NEUROG3, as described previously) four genes were also immune disease related genes: GUCY2, EPCAM, MYO5B, and TNF. The gene discussed is PYY; the disease is glycogen storage disease VI.