IL6 and breast carcinoma: Serum TNF-α and IL-6 levels were significantly higher in cats with mammary carcinoma compared to healthy controls (P = 0.011 and P = 0.021 respectively; Fig. 2a,b), being detectable in all cats with mammary carcinoma enrolled in the study, showing a median of 36.10 pg/mL (range 19.11–463.5 pg/mL) and 65.94 pg/mL (range 39.17–766.5 pg/mL), respectively.