LIF and neoplasm: The multifaceted cooperation of tumor cells and TAMs is exemplified by signal transducer and activator of transcription 3 (STAT3)-inducing cytokines IL-10, IL-6, and LIF, all of which are predictive of a poor survival: while the major source and target of IL-10 are TAMs, LIF is synthesized by, and acts on, tumor cells, whereas IL-6 production and action are not cell type selective (52).