Changes in NK cell number and function. (A) Infusion of rhIL-15 and mogamulizumab led to increased circulating NK cell numbers within 1 week and increased CD69 expression, a marker of activation, which peaked around day 5. (B) Activating NK cell receptors NKG2D, NKp30, NKp46, and DNAM1 were assessed at baseline and after treatment. (C) NK cells obtained after 5 days of rhIL-15 and mogamulizumab demonstrated increased cell lysis ex vivo when cultured with CD20 antibody-coated Raji cells.