MKI67 and neoplasm: ELISA results revealed that cats with sHER2 levels ≥10 ng/ml were significantly associated with the early stage of the disease (stage I, p = 0.006; Odds Ratio [OR] = 17.9; 95% CI: 1.633-984.42), absence of tumor necrosis (p = 0.0024; OR = 9.28; 95% CI: 1.79-60.61) and lower Ki-67 values (< 14%, p = 0.007; OR = 7.73; 95% CI: 1.57-47.54).