Figure 2 summarizes the key cytokines that are elevated and involved in IBD and are also implicated in HF, including tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-12 (IL-12), interleukin-23 (IL-23), and interleukin-17 (IL-17). This evidence concerns the gene IL17A and inflammatory bowel disease.