<prompt> All of the following are true about type 1 HLA except?Present on APCActivate cytotoxic T cell and kill virus infected cellPresent on nucleated cellsFirst line defense mechanism  <response>: Ans. d First line defense mechanismRef: R 9thpg 191a. True; It is present on all nucleated cells including antigen presenting cells as well as plateletsb. True; It activates cytotoxic T cell and kill virus infected cellc. True; It is present on platelets also, which are non- nucleated cellsd. False; It is a part of adaptive immunity second line defense mechanism 