CD8A and neoplasm: The expression of PD-L1 (HR: 0.370, 95%CI: 0.150–0.911, P = 0.031) and CD8+ T cells (HR: 0.409, 95%CI: 0.185–0.900, P = 0.026) were independent protective factors affecting RFS of GIST patients, but tumor size was not an independent risk factor (Table 4).