C3 and autoimmune polyendocrinopathy: IHC studies performed after the MRI studies showed the presence of USPIO-conjugated anti-C3 antibodies in the placenta of APS mice (Figure 1c) and in the foetal brain of APS (Figure 1d) and PTB mice injected with USPIO-anti-C3 (Figure 1e) compared with their respective controls (mIgG-treated mice and age-matched controls).