All of the following about NK cells are true, except:

NK cells/ Null cells: Destroy irreversibly stressed and abnormal cells, such as virus-infected cells and tumor cells. They make up approximately 5% to 10% of peripheral blood lymphocytes. They do not express TCRs or Ig. CD16 and CD56, are commonly used to identify NK cells CD16 is an Fc receptor for IgG, and it confers on NK cells the ability to lyse IgG-coated target cells. NK cells secrete cytokines such as interferon-g (IFN-g), which activates macrophages to destroy ingested microbes.