Transcription: B cell. Lymphocytes are the cells in the body that are intimately involved in the immune response. They occur in the blood, in lymph nodes and in various organs. The two types of lymphocytes are B cells and T cells. Special techniques are needed to tell them apart because they look the same when viewed by ordinary methods under the microscope. It may be essential to make this distinction in cases of lymphomas since the treatment and prognosis of B cell lymphomas may be very different than that of T cell lymphomas. you