CD4 and nasopharyngeal carcinoma: Flow cytometric analysis of the 12 mm spinal cord region spanning the injection site revealed a significant (p<0.01) reduction in CD4+ T cell frequency within the CNS of EB-NPC transplanted animals compared to controls, indicating dampened CD4+ T cell accumulation as a result of transient EB-NPC engraftment (Fig 3A and 3B).