 - Apheresis a procedure for collecting immune cells called lymphocytes to measure the immune response to treatment. Apheresis is done three times: before starting the study and again around study days 99 and 183. For this procedure, blood is collected through a needle in an arm vein. The blood circulates through a machine that separates it into its components by spinning, and the lymphocytes are extracted. The rest of the blood is returned to the patient through the same needle. This will only be done in participants who have the tissue marker HLA-A2 about 50 of patients. 