 RESTORE is an observational, open-label, multi-center, prospective, study enrolling Raptiva efalizumab treated patients with moderate to severe chronic plaque psoriasis. The overall duration of the study is approximately 4 years. Patients will be followed from the time of study enrolment to studytreatment termination; thus active follow-up period will vary across subjects. Raptiva efalizumabtreated patients with moderate to severe chronic plaque psoriasis and meeting the inclusionexclusion criteria specified will be eligible for participation in this study. 