CD8A and neoplasm: This is enhanced by IR and this leads to more T-cell infiltration into tumor tissues.285–287 It is reported that the density of CD3+ and CD8+ lymphocytes in tumor site is associated with disease-free and overall survival in patients treated with chemoradiotherapy for rectal cancer.87 More recently, Dovedi et al.288 found that low-dose RT combined with PD-1 blockade can promote the migration of T-cells to primary treated sites and augment tumor regression.