The metabolism of tumors in the body is discussed by Otto Warburg, Franz Wind, and Erwin Nägelein. They explore whether tumor cells can be killed by lack of energy and how tumors are supplied with oxygen and glucose. Tumor cells obtain energy through respiration and fermentation. Respiration breaks down organic materials into carbon dioxide and water, while fermentation converts glucose into lactic acid. All tested tumors behave similarly, regardless of type. Tumor cells can survive without oxygen in glucose-containing serum. Pieces of Flexner carcinoma and Jensen sarcoma could be transplanted after oxygen deprivation. However, respiration alone can sustain tumor cells. Dialyzing serum without glucose and oxygen showed that tumor cells could resume normal metabolism when glucose and oxygen were reintroduced. Killing tumor cells requires stopping both respiration and fermentation. Tumor cells deprived of oxygen and glucose for several hours were killed, and metabolism ceased. This was confirmed in experiments where tumor animals were deprived of oxygen and glucose, leading to cell death. In living animals, tumor cells are more adaptable in energy production than normal cells. However, the tumor's glucose and oxygen supply is less efficient than normal tissues. Tumor cells are more sensitive to energy deprivation than normal cells, as the tumor as a whole is more vulnerable than the organism. Tumor tissues are poorly supplied with glucose compared to normal tissues. The glucose concentration in tumor veins drops to about 57% of arterial levels. Tumors take about 70 mg of glucose per 100 cc of blood, while normal tissues take only 2-16 mg. Lactic acid formation in tumors is significant. Tumor veins contain more lactic acid than arteries, indicating lactic acid production as blood passes through the tumor. Tumors produce about 46 mg of lactic acid per 100 cc of blood. Tumor respiration is affected by oxygen levels in tumor veins. Tumor cells use about 66% of glucose for fermentation and 34% for respiration. Fermentation is more sensitive to glucose concentration changes. Increasing glucose levels in tumor veins can enhance fermentation. Tumor cells can survive without glucose, as they obtain oxygen from the blood. Experiments showed that tumor cells remained viable even with low blood sugar levels. Tumor cells in insulin-induced hypoglycemia showed normal respiration and fermentation. Tumor cells can be killed by lack of oxygen. Cutting tumors into arterial and venous halves showed that the venous half, deprived of oxygen, died. This suggests that oxygen deprivation in the tumor's venous part kills both tumor cells and capillary cells, leading to tumor necrosis. Tumor cells can be killed by lack of oxygen, but this requires stopping both respiration and fermentation. Tumor cells in the venous half of the tumor die due to oxygen deprivation, leading to tumor necrosis. This shows that tumor cells are more sensitive to oxygen deprivation than normalThe metabolism of tumors in the body is discussed by Otto Warburg, Franz Wind, and Erwin Nägelein. They explore whether tumor cells can be killed by lack of energy and how tumors are supplied with oxygen and glucose. Tumor cells obtain energy through respiration and fermentation. Respiration breaks down organic materials into carbon dioxide and water, while fermentation converts glucose into lactic acid. All tested tumors behave similarly, regardless of type. Tumor cells can survive without oxygen in glucose-containing serum. Pieces of Flexner carcinoma and Jensen sarcoma could be transplanted after oxygen deprivation. However, respiration alone can sustain tumor cells. Dialyzing serum without glucose and oxygen showed that tumor cells could resume normal metabolism when glucose and oxygen were reintroduced. Killing tumor cells requires stopping both respiration and fermentation. Tumor cells deprived of oxygen and glucose for several hours were killed, and metabolism ceased. This was confirmed in experiments where tumor animals were deprived of oxygen and glucose, leading to cell death. In living animals, tumor cells are more adaptable in energy production than normal cells. However, the tumor's glucose and oxygen supply is less efficient than normal tissues. Tumor cells are more sensitive to energy deprivation than normal cells, as the tumor as a whole is more vulnerable than the organism. Tumor tissues are poorly supplied with glucose compared to normal tissues. The glucose concentration in tumor veins drops to about 57% of arterial levels. Tumors take about 70 mg of glucose per 100 cc of blood, while normal tissues take only 2-16 mg. Lactic acid formation in tumors is significant. Tumor veins contain more lactic acid than arteries, indicating lactic acid production as blood passes through the tumor. Tumors produce about 46 mg of lactic acid per 100 cc of blood. Tumor respiration is affected by oxygen levels in tumor veins. Tumor cells use about 66% of glucose for fermentation and 34% for respiration. Fermentation is more sensitive to glucose concentration changes. Increasing glucose levels in tumor veins can enhance fermentation. Tumor cells can survive without glucose, as they obtain oxygen from the blood. Experiments showed that tumor cells remained viable even with low blood sugar levels. Tumor cells in insulin-induced hypoglycemia showed normal respiration and fermentation. Tumor cells can be killed by lack of oxygen. Cutting tumors into arterial and venous halves showed that the venous half, deprived of oxygen, died. This suggests that oxygen deprivation in the tumor's venous part kills both tumor cells and capillary cells, leading to tumor necrosis. Tumor cells can be killed by lack of oxygen, but this requires stopping both respiration and fermentation. Tumor cells in the venous half of the tumor die due to oxygen deprivation, leading to tumor necrosis. This shows that tumor cells are more sensitive to oxygen deprivation than normal