CD8A and Chediak-Higashi syndrome: Of note, patient 7 had over 10 LU NK cell cytotoxicity, which corresponded to the highest NK cell and CD8+CD57+ T cell exocytosis among the CHS patients (and within the normal range for healthy pediatric patients), although her sister (patient 8) displayed lower NK cell and CTL exocytosis as well as NK cell-mediated cytotoxicity.