In HIV-infected infants, CD56+CD16+ cells declined at a rate of –1.3% per month (p < 0.001) in parallel with an increase in CD56-CD16+ cells at a rate of +1.1% per month (p < 0.001), consistent with the current hypothesis that CD56+CD16+ cells lose CD56 expression in response to persistent stimulation during chronic viral infection (Alter et al., 2005; Björkström et al., 2010). This evidence concerns the gene NCAM1 and viral infectious disease.