Leukemia is a malignant tumor of the hematopoietic system, commonly known as “blood cancer”, and is one of the most common malignant tumors. It is characterized by the tumorigenic proliferation of a certain type of leukemia cells in the bone marrow or other hematopoietic tissues, which can infiltrate various organs and tissues in the body, impairing the function of each organ and producing the corresponding symptoms and signs. Clinical symptoms include anemia, fever, infection, bleeding, and enlargement of the liver, spleen and lymph nodes to varying degrees. Infantile cells may appear in the bone marrow and peripheral blood. The latest issue of Nature (June 27), titled “Outlook: Leukaemia,” features information on the classification of leukemia, age of onset, molecular oncology research, cancer stem cell research, drug safety, establishment of stem cell banks, and genetically engineered immune cell therapies. The content Leukemia classification and age of onset Leukemia can be classified into two major groups, acute and chronic, according to the degree of leukemic cell differentiation. Depending on the type of cells involved, there are categories such as granulocytic, monocytic, and lymphocytic leukemias. Among them, chronic myeloid leukemia (CML) accounts for 13%, acute granulocytic leukemia (AML) for 28%, chronic lymphocytic leukemia (CLL) for 30%, acute lymphoblastic leukemia (ALL) for 13%, and other/non-specific for 17%. Most leukemias develop in middle and old age, with some disseminated and relatively few cases developing in childhood. Leukemia stem cell research Deep in the spongy bone marrow fills a large number of resting cells that can generate all the blood cells of the body. People call these primitive cells hematopoietic stem cells, and they have the ability to divide indefinitely. In the 1990s, John Dick, a cancer researcher at the University of Toronto in Canada, was the first to isolate leukemia stem cells. There is growing evidence that immortalized stem cells drive certain types of leukemia and other cancers in a similar way. Just as hematopoietic stem cells can generate a large number of blood cells, leukemic stem cells can generate the wide variety of malignant cells seen in cancer. In earlier years, many cancer researchers believed that all cancer cells had the same ability to generate new cancers. However, in recent years, cancer stem cell models have been proposed that only a rare subpopulation of cells has the ability to generate new tumors. These cells are self-renewing, long-lived, and can remain in a resting state for many years. Conventional treatments may be able to kill most cancer cells and induce cancer regression, but the presence of cancer stem cells can cause seemingly healthy individuals to have a resurgence of the disease. This model has sparked intense debate over the past decade, though. Finding the Achilles’ heel of these all-powerful cells and removing them has certainly become an important direction for cancer researchers conducting research on leukemia treatment. Epigenetics: a reversible marker Past research on cancer has typically focused on genetics, attributing the cause of the disease to genetic mutations that cause cells to grow indefinitely or prevent tumor cells from dying. However, recent findings in leukemia have begun to shift the focus from genetics to epigenetics. Researchers have found that the origin of many leukemias can be traced to mutations in epigenetic modifying enzymes. Scientists believe that it is easier to develop corresponding inhibitors for these enzymes, and therefore a promising therapeutic direction. Leukemia treatment Most solid tumors are replete with many mutations, making it impossible to clearly understand exactly which mutation is pushing the cell down the wrong path and which one should be the target of cancer treatment. Leukemia may seem relatively straightforward: chronic myeloid leukemia (CML) is caused by a single gene fusion. imatinib (imatinib) was approved for CML in 2011, and it improved 5-year survival rates for CML by more than 95 percent. Many children with acute lymphoblastic leukemia also survive. However, in recent years it has been found that some CML patients have developed resistance to imatinib, and doctors have had to switch to other drugs for treatment. And for many leukemias, doctors are still treating with some of the toxic therapies from the 1970s. Children with leukemia suffered serious and even life-threatening complications after receiving these treatments. Current progress in new treatments has been relatively slow. Some scientists have used genetically engineered immune cells to destroy cancer cells, and so far have reported cures for about fewer than a dozen patients. Bone marrow transplants and cord blood transplants are also routine treatments for leukemia. A number of other drug candidates targeting epigenetic alterations show therapeutic promise.