IL18 and neoplasm: Strikingly, the levels of HMGB1, IL-18, and IL-1β were all elevated in the serum of treated mice and while an anti-IL-1β antibody markedly inhibited tumor regression, anti-IL-18 and anti-HMGB1 antibodies exhibited only a partial- and non-inhibition of tumor regression, respectively, indicating that IL-1β plays a significant role in promoting antitumor immunity.