IL17A and inflammatory bowel disease: By examining critical cytokines associated with the progression of IBD and CRC [19, 20], we detected increased serum levels of proinflammatory cytokines such as IL‐6, IL‐23, IL‐17A and TNF‐α in mice during the early stage of intestinal inflammation progression, namely, at the 2nd and 6th weeks (Fig. 6A–D).