Final answer:
Leukemia is cancer characterized by the overproduction of leukocytes, which can be mature or immature and impairs the immune system.
Step-by-step explanation:
It is characteristic of leukemia to be accompanied by a massive proliferation of leukocytes. Leukemia is a type of cancer that starts in the bone marrow, leading to the production of abnormal blood cells, most commonly white blood cells. There are different types of leukemia, including myelocytic leukemia, which arises from myeloid stem cells, and lymphocytic leukemia, from lymphoid stem cells. Chronic leukemia involves the accumulation of mature leukocytes, while acute leukemia is marked by the overproduction of immature leukocytes. Both conditions impair the cells' normal functions, making patients susceptible to infections and other health issues.