This test utilizes flow cytometry to detect and quantify the expression of CD7, a surface antigen expressed on T-lymphocytes and early myeloid precursor cells. CD7 is a pan T-cell marker commonly used to identify T-cell populations in peripheral blood, bone marrow, or tissue samples. Additionally, its expression on early myeloid cells makes it a valuable marker for evaluating hematopoietic progenitor cells and certain leukemic or dysplastic conditions.