However, although Selplg-/- mice sustained greater numbers and frequencies of effector and memory T cells throughout the course of viral infection, with an adoptive transfer approach to prime WT and Selplg-/- T cells together in a PSGL-1-sufficient environment by LCMV Arm infection, they failed to mount a detectable memory effector response to a secondary viral challenge in naïve hosts as indicated by a failure to recover Selplg-/- T cells compared to WT T cells. The gene discussed is SELPLG; the disease is infection.