POU5F1 and neoplasm: Indeed, the co-expression of Oct4/Sox2 inhibits the expression of the C-C Motif Chemokine ligand 5 (CCL5) and C-X-C Motif Chemokine ligand 9, 10 and 11 (CXCL 9,10 and 11), which mediate CD8+ T cell attraction against tumor cells [66].