An ELISA analysis confirmed our findings that 10 mg/kg AR‐42 treatment did not have a strong impact on the variable circulating IL‐6 levels associated with C‐26 tumor burden (Fig 6A), and further demonstrated serum IL‐6 levels were not associated with effects on body weight in treated, C‐26 tumor‐bearing mice at sacrifice (r2 = 0.018, P = 0.48). Here, IL6 is linked to neoplasm.