To address this possibility we transferred WT OT1 cells into congenic hosts that were then infected with LM-OVA and treated with the IgG control or the anti-BTLA mAb at days 27, 30 and 34 p.i. Interestingly, blockade of the HVEM-BTLA interaction at these late times after LM-OVA infection did not affect the maintenance of memory OT1 cells. This evidence concerns the gene BTLA and infection.