The literature contains conflicting results, as presented above, so we suggest that the higher abundance of PCDH17 in the neoplasia groups from our study could be due to the heterogenicity of this protein in EV-enriched samples from tissue and serum samples, and given its role in women with breast cancer, this protein should be further investigated and validated in serum and tissue from bitches with a mammary tumor, in order to improve the accuracy of these findings. The gene discussed is PCDH17; the disease is breast cancer.