IL1B and neoplasm: Anakinra (Kineret), a recombinant soluble IL-1 receptor antagonist, blocked IL-1β secretion in MPL-pSi treated mice (Figure 6d) and reduced the anti-tumor efficacy of the microparticles, however, due the small number of mice used in the study, tumor size in these mice was not significantly different from that of control animals (n = 3/group; Figure 6e).