STAT1 and autoimmune polyendocrinopathy: However, compared with the 160 μg/ml APS group, 320 μg/ml APS treated group showed a certain downward trend in p-STAT1, with MFI values of (853.17 vs 630.17, p< 0.01) (Figure 8B); p-STAT3 did not change much (182.50 vs 182.33, p > 0.05) (Figure 8D).These results showed that APS markedly elevated the phosphorylation levels of STAT1, STAT3 in MDSC and in a dose-dependent manner.