While many aging biomarkers exist—including those related to cell senescence (e.g., p16), epigenetic changes (e.g., epigenetic clocks), telomere shortening (e.g., telomere length), and inflammation (e.g., IL-6, CRP) [15]—and are promising measures to be utilized in the above capacities in cancer survivor populations, there is no consensus as to which biomarkers are valid and reliable measures in the context of cancer and its treatment. This evidence concerns the gene IL6 and cancer.