In a subsequent study, an increased concentration of neutralizing autoantibodies against granulocyte macrophage colony-stimulating factor (GM-CSF Ab) was observed in a population of adult and pediatric CD patients, however, GM-CSF Ab level was found to be especially elevated among subjects with ileal disease involvement and the stricturing CD phenotype (p < 0.001). This evidence concerns the gene CSF2 and Cowden disease.