CD28 and relapsing-remitting multiple sclerosis: Cryopreserved PBMCs from 20 healthy controls, 20 untreated patients with RRMS and 20 patients treated with cladribine at W52 and W96 were stimulated for 48 h with the autoantigens MOG, MBP, CRYAB (for 8 patients from each group), or RASGRP2 together with co-stimulatory anti-CD28 or medium with anti-CD28 alone as control.