ICAM1 and infection: Nevertheless, once entering the ICAM-1/2-/- MedLNs following infection and without α4 blocking, the accumulating OT-I CD8+ T cells underwent enhanced differentiation into effector IFN-γ producing CD8+ T cells (Figures 6G–J) similar to the enhanced CD4+ T cell differentiation into Tfh cells observed in infected ICAM-1/2-/- mice (Figure 5B).