CD28 and Autoimmunity: This notion was further supported by the comparable expression of antigens, including immunoreactive class I major histocompatibility complex (H2kl), high mobility group box 1 (Hmgb1), and T-cell co-stimulatory molecule CD28 (Fig. S1C), that can be detected in some 10.13039/501100007125IIM patients with high autoimmunity [36,37].