Presence of several cytokine-like molecules in molluscan hemocytes

The presence of a variety of cytokine-like molecules (IL-1 alpha, IL-1 beta, IL-2, IL-6, TNF-alpha) in the hemocytes of two molluscs, i.e., Planorbarius corneus and Viviparus ater, is reported. These molecules are present only in hemocytes with phagocytic activity. These data, together with recent reports on the presence of cytokine-like molecules in other invertebrates, suggest that cytokines are important, ancestral and functionally conserved molecules.