NCIt definition : A recombinant therapeutic agent which is chemically identical to or similar to the
endogenous cytokine interleukin-9 (IL-9). Produced by CD4 lymphocytes, IL-9 stimulates
the proliferation of T-helper cells and the growth of mast cells and megakaryoblasts.
This agent also enhances the growth of some leukemia cell lines and may play a role
in the pathogenesis of Hodgkin disease and large cell anaplastic lymphoma. (NCI04);