CD3: UCHT1 antibody reacts with a combinatorial epitope of CD3epsilon, a 20 kD chain of the CD3/T-cell receptor (TCR) complex found on all mature T lymphocytes, NK-T cells and some thymocytes.CD16: 3G8 antibody reacts with CD16, a 50-65 kD transmembrane or a 48 kD GPI-anchored glycoprotein that is a member of the immunoglobulin superfamily. CD16 is expressed on NK cells, activated monocytes, macrophages, mast cells and neutrophils.CD56: MEM-188 antibody reacts with the 175 - 185 kD isoform of CD56, N-CAM (Neural Cell Adhesion Molecule), which is expressed on NK cells and a subset of CD3+ T cells. CD56 is also expressed in brain (cerebellum and cortex) and at neuromuscular junctions. Certain large granular lymphocyte (LGL) leukemias, small-cell lung carcinomas, neuronal derived tumors, myelomas, and myeloid leukemias also express CD56.