CD28 and myeloid sarcoma: No differences were found in the percentages of PBMCs positive ErbB4 between MS patients and HC after stimulation with anti-CD3/CD28 mAb (average percentages for MS patients ± S.D = 13.2 ± 9.7, P = 0.038 and in HC = 13.0 ± 6.0, P < 0.001).