Fig. 4. The location of the LFA-1 conformation zones on a T cell migrating on ICAM1. The leading edge of the T cell expresses low levels of LFA-1 with intermediate affinity for ICAM1 that is recognised by monoclonal antibody (mAb) KIM127 (Stanley et al., 2008). The focal zone expresses higher levels of LFA-1, which is in the high-affinity conformation recognised by both mAb KIM127 and mAb 24 (Smith et al., 2005; Stanley et al., 2008). The uropod at the rear expresses the highest level of LFA-1, but little is known of its binding activity.