<prompt> Which of these is CD marker of cytotoxic cells?CD8CD4CD1aCD1  <response>: Ans. a CD8Ref: Robbins 9thpg 191; 8thpg 186CD8Is a marker for cytotoxic T cellsActs as a co-receptor for TCRBinds to HLA-I to cause cytotoxic effect on virus infected and tumor cells 