However, it has been proposed that chemotactic movement is halted and even chemorepulsive movement can be triggered at above a certain level of CXCL12.[27] As CXCL12 was expressed in senescent tumor cells, it was tempting to speculate that the CXCL12 secreted from senescent tumor cells might influence intratumoral CD8+ T cell infiltration. This evidence concerns the gene CXCL12 and neoplasm.