This increase in granulocytes was also reflected in a proportionate decrease in the frequency of lymphocytes in BAL of children with CF relative to healthy controls [NK cells (median 0.22% vs 0.86%, p = 0.024), CD8 T cells (median 0.55% vs 7.19%, p = 0.0041), and CD4 T cells (median 1.18% vs 5.4%, p = 0.024). Here, CD4 is linked to cystic fibrosis.