CXCL8 and ulcerative colitis: Recent studies have confirmed that the main characteristic of ulcerative colitis is that the intestinal wall is infiltrated and continuously activated by a large number of inflammatory cells, for which the occurrence and development are closely related to a variety of inflammatory factors such as interleukin-6 (IL-6), interleukin-8 (IL-8), high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor (TNF)-α [2].