The novel observation of this work is that IL17-A promotes intracellular ROS accumulation by inducing mitochondrial dysfunction while inducing pyroptosis by activating the ROS/NLRP3/capsase4/GSDMD pathway, upregulating the release of inflammatory factors such as IL-1β, IL-18 and immune antigens into the tumour microenvironment, and recruiting CD8 + T cells to infiltrate the tumour in colorectal cancer. The gene discussed is CD8A; the disease is colorectal cancer.