CD8A and neoplasm: Interestingly, one study showed that activated PSCs secrete C-X-C motif chemokine ligand 12 (CXCL12) to sequester CD8+ T cells, reducing CD8+ T-cell infiltration in the juxtatumoural compartment (identified as <100 μm from the tumour) (Ene-Obong et al., 2013).