CD33 and neutropenia: We also found that levels of proteins related to T lymphocytes (CD2, CD3D, CD3E, CD5, CD247), platelets (CD41, CD42b), and neutrophils (CD11b, CD18, CD33, CD66b) were reduced in patients with T cell lymphopenia, thrombocytopenia, and neutropenia, respectively, and could be clustered as distinct groups (Fig. 6), suggesting that assays of these proteins could be used to identify patients with these cell-phenotypical alterations.