DURING our investigations on the protein metabolism of schizophrenic patients, a number have been found who exhibited a specific, pathological pattern of emotional response to stress and abnormally high concentrations of a proteolyticenzyme inhibitor in the serum. The studies of West and associates1 have demonstrated a relationship between the concentrations of this substance, rennin (human pepsin) inhibitor, and those of another, chymotrypsin inhibitor, and the rate of growth of cancer. The higher the titer of rennin inhibitor and the lower that of chymotrypsin inhibitor, the slower is the growth of the neoplasm. On the other hand, if the concentration of chymotrypsin inhibitor approaches or exceeds that of rennin inhibitor, the rate of growth is proportionately increased. Comparable relationships have been found between the relative concentrations of these enzyme inhibitors in active and in arrested pulmonary tuberculosis.2
Acute infections, physical traumas, and burns are accompanied by high chymotrypsin- and