Anti-inflammatory cytokines detected in the tissue culture supernatant. IL-1β triggered an anti-inflammatory response evidenced by elevated interleukin-1 antagonist (IL-1RA), interleukin-4 receptor alpha (IL-4Rα), and IL-13 levels. IL-1RA significantly increased to day 3 in response to hyperacute serum treatment, but decreased until day 5, n = 12 (A). The significance level was p < 0.05, where * means that the p-value was between 0.05 and 0.01, ** means that p-value was between 0.01 and 0.001, and *** means that the p-value was lower than 0.001. The correlations of cytokine changes are presented in heatmap tables. Very strong correlations were found among all three anti-inflammatory cytokines (B).