Chemoresistant lung cancer cell-derived IL-34 activates an autocrine pathway, which enhances the survival of neoplastic cells, but at the same time, promotes the in vitro differentiation of monocyte-derived M2-polarized macrophages and enhances the immunosuppressive function of TAMs through a C/EBPβ-mediated mechanism [67]. The gene discussed is IL34; the disease is lung cancer.