The Sponsor has made a decision, driven by business needs, to cease promotion, manufacturing, distribution and sales of Amevive

Subjects exposed to alefacept are to be enrolled. Subjects will be contacted every 6 months to gather general health information.

There are no study-mandated tests, visits or clinical interventions after the 1st (enrolling) visit. After the patient is enrolled in the study, they will be contacted every 6 months to complete structured telephone interviews conducted by the ATLAS Study Center.

Inclusion Criteria:

• Psoriasis patients who are prescribed alefacept consistent with product labeling are eligible for enrollment.

Patients treated with alefacept for chronic plaque psoriasis