IL6 and neoplasm: Some evidences indicate that cytotoxic chemotherapy enhances tumor recurrence by induction in TNBC cells of pro-tumorigenic factors, including TGFβ, interleukin 6 (IL-6), IL-8, IL-1β, tumor necrosis factor-α and granulocyte-macrophage colony-stimulating factor (GM-CSF), which stimulate CSCs expansion [91,92].