The aim of the present study was to evaluate the predictive value of circulating free (as detected by the R&D Systems Hsp70 ELISA) and exosomal Hsp70 (as detected by the compHsp70 ELISA/Hsp70-exoELISA) in different animal species as a potential biomarker for pre-cancerous lesions and malignant tumors. This evidence concerns the gene HSPA1A and cancer.