Figure 4. Cytokine secretion by SV40-HCEs cultured under 20% O₂ (control group) or 2% O₂ (hypoxia group) stimulated with LPS. The culture medium was collected 24 h after LPS exposure and analyzed for the presence of IL-6 and IL-8 proteins using ELISA. The p-values were calculated using a two-tailed paired t tests. The triple asterisk indicates a p<0.001).