There are three basic statements in the field of stem cell research. Which statement best describes current stem cell research? Consider these examples. These statements may be true for a specific situation. During an immune response, the body produces several chemical messengers. Different types of cells release these messengers, including macrophages as well as lymphocytes. These messengers are released by certain cells to combat infection. However, the immune system needs to maintain balance. Consequently, excessive amounts of certain mediators can cause harm.