Interleukin 9 receptor (IL9R) accepts IL9, a pleiotropic cytokine, belonging to the group of interleukins, through the signaling transduction proteins HOOK2, FLII, E2F4 in DLBCL ABC and DLBCL GCB, to upregulate TF FOXL1. The gene discussed is E2F4; the disease is diffuse large B-cell lymphoma.