CD9 and nutritional deficiency disease: On the other hand, subjects with MNA ≤ 23.5 showed lower concentrations of immune cell-derived total CD9+ and CD9+/AV+, and higher concentrations of CD40+/AV+ and CD16+/AV– cMV compared to subjects adequately nourished (P ≤ 0.043, all), suggesting altered immune functionality in subjects with malnutrition.