Given that the survival of 2W1S-specific memory T cells was not significantly impaired by anti-OX40L Abs, expression of OX40 by 2W1S-specific CD4+ T cells during the response to Lm-2W infection was assessed, with total CD4+ Treg cells used as a positive control for OX40 detection (Fig.1C). Here, TNFSF4 is linked to infection.