CD8A and pancreatic ductal adenocarcinoma: Studies have shown that regular moderate-intensity aerobic exercise can increase the number of CD8+ T cells in mice with breast cancer, enhance their trafficking ability and infiltration into tumors, thereby strengthening their anti-tumor capacity (Gomes-Santos et al., 2021); Furthermore, in a pancreatic ductal adenocarcinoma mouse model, it has also been shown that aerobic exercise can promote the infiltration of CD8+ T cells into the tumor microenvironment of both pancreatic ductal adenocarcinoma mice and patients, slowing down the tumor growth rate (Kurz et al., 2022).