IBD is also characterised by the chronic release of pro-inflammatory cytokines such as IL-6 and tumour necrosis factor-α (TNF-alpha)—the increased production of these cytokines can stimulate the receptor activator of nuclear κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) axis and thus drive osteoclastic bone resorption [9,10,11]. This evidence concerns the gene TNFSF11 and inflammatory bowel disease.