Results revealed that serum ObR levels were significantly higher in animals with mammary carcinoma than in controls, independently of molecular subtype (control group 15.67 ng/ml; luminal A 23.04 ng/ml, p < 0.0001; luminal B 20.18 ng/ml, p < 0.001; HER2-positive 28.99 ng/ml, p < 0.0001; triple-negative 21.70 ng/ml, p < 0.0001; Figure 4A). Here, ERBB2 is linked to breast carcinoma.