Immunohistological demonstration of the same type of pyruvate kinase isoenzyme (M2-Pk) in tumors of chicken and rat

Tumors of chicken and rat contain the M2-type of pyruvate kinase isoenzyme. The amount of this isoenzyme is significantly higher in malignant tumors compared with benign tumors. No alteration of the normal pyruvate kinase isoenzyme pattern was found in hyperplastic tissue.