IL6 and cancer: Moreover, a wide variety of pro-inflammatory factors, e.g., interleukin-6 (IL-6), interleukin-1 (IL-1), tumour necrosis factor-alpha (TNF-a), and transforming growth factor-β (TGF-β), which are secreted by cancer and tumour-associated immune cells, contribute to the occurrence of disease-associated adverse outcomes that deteriorate patients’ functional ability and quality of life [3,4].