STAT3 and neoplasm: Autocrine IL-6 secretion is linked to poor prognosis, driving tumor growth and invasion through: (1) direct stimulation of glioblastoma cell proliferation and survival; (2) STAT3 activation, which promotes tumor cell proliferation, inhibits apoptosis, and suppresses immune cell function; and (3) a cytokine feedback loop involving IL-6 and IL-10, sustaining tumor growth and impairing anti-tumor immunity (62), indicating IL-6 is a promising therapeutic target.