TNF and neoplasm: Apyrase is a calcium-activated plasma membrane-bound ATP diphosphohydrolase that catalyzes the hydrolysis of nucleotides like ATP to AMP and inorganic phosphate.53 Removing extracellular nucleotides with apyrase treatment has been shown not only to prevent IL-1β accumulation, but also the production of inflammasome-independent cytokines such as TNF.54 The secretion of TNFα by DCs after contact with SN of B16 tumor cells that have been treated with zVAD-fmk was also dependent on both nucleotides and TLR signaling (Figures 4c2 and c1).