Under normal circumstances, the size and morphology of cells from the same tissue are basically the same, but cancer cells are generally larger than the corresponding normal cells, and the size and morphology of cancer cells are also very different from each other, and sometimes there are “tumor giant cells” with large size. All cells contain nucleus and cytoplasm. Under normal conditions, most cells have only one nucleus and a certain ratio of nucleus to cytoplasm. In cancer cells, the nucleus is enlarged and inconsistent in shape, and may be meganucleated, binucleated, multinucleated, or heterogeneous. The quality and quantity of cytoplasm of cancer cells are also different from those of normal cells. Any living cell has to carry out metabolism to maintain the life of the cell. Cancer cells are also a kind of living cells, and their metabolic characteristics are very different from those of normal tissue cells. The metabolic characteristics of cancer cells are very different from those of normal tissues. They show that the synthesis of basic cellular structures such as proteins and nucleic acids is abnormally vigorous, while their catabolism is significantly reduced, resulting in the imbalance between synthesis and catabolism. The enhanced metabolism of cancer cells is also one of the reasons why cancer is harmful to human body. For example, the protein metabolism of cancer tissues is highly developed, especially the protein synthesis is greatly enhanced, and even the protein breakdown products of normal tissues are seized to synthesize the proteins needed by cancer tissues themselves, as a result, cancer patients can be in a cachectic state of severe depletion. 3. Different ways of cell growth Firstly, the autonomy of cancer cell growth. When cells are artificially cultured, it is found that normal cells stop dividing when they come into contact with surrounding cells in the process of division and reproduction, a phenomenon called “contact inhibition” of cell proliferation, which can inhibit the excessive proliferation of cells. Cancer cells, to varying degrees, are out of control of the body and often show uninterrupted growth, multiplication and poor differentiation, which is called “autonomy” or “autonomous growth” of your cells. In the process of cancer development, “autonomy” is always increasing, and the faster the growth, the faster the development. The second characteristic of cancer cell growth is infiltration and metastasis. This is the main feature to distinguish benign and malignant tumors, only malignant tumors have infiltration and metastasis. Normal cells have a certain adhesion to each other. The surface of cancer cells can undergo a series of changes to reduce the adhesion between cells, and cancer cells can easily shed, dissolve and invade the surrounding tissues, or invade the blood and lymphatic tissues, and spread to other parts of the body through the circulation of blood and lymphatic fluid, resulting in the spread and metastasis of cancer. 4. Inheritance of cancer cell characteristics Cancer cells can inherit their autonomous, infiltrative and metastatic characteristics to their offspring cells. Therefore, the cancer cells can expand and even spread widely. The malignant characteristics of cancer cells are always maintained.