STAT3 and neoplasm: It is well known that both tumor tissue and PCa patients serum have high levels of IL-6.20 It is also demonstrated that IL-6 stimulation boosts PCa proliferation assistant with signal transducer and activator of transcription 3 (STAT3)-activated signaling pathway.21 Furthermore, it has a role in regulating stemness, and studies showed that siltuximab treatment, which inhibits STAT3, suppressed the clonogenicity of PCa stem cells.13,22