In the CGD-zymA mice, which are characterized by the absence of a respiratory burst32, in parallel with attenuated increases in the EPO and macrophage EPOR and p-Jak2 levels (Fig. 1e–h, Supplementary Fig. 1d–h), the HIF-1α and hypoxia enhancement in exudate leucocytes and peritoneum during acute peritonitis were greatly suppressed compared with the WT-zymA mice (Fig. 2a,c, Supplementary Fig. 2c), suggesting an essential contribution of respiratory burst to local hypoxia during peritonitis. Here, EPO is linked to peritonitis.