FTO and obesity due to melanocortin 4 receptor deficiency: For example, obesity-linked non-coding SNPs in the fat mass and obesity-associated gene (FTO) are spatially connected [i.e., they are physically interacting in a manner, which can be captured by proximity-ligation techniques (e.g., 4C-seq)] to promoters at the Iroquois homeobox 3 (IRX3) gene.