CD4 and precursor B-cell acute lymphoblastic leukemia: Furthermore, flow cytometric analysis of T cells in peripheral blood of 45 children with B-ALL (13% with acute EBV infection and 31% with latent infection), and 40 healthy controls (10% with chronic EBV infection) in Egypt showed that patients had higher proportions of CD4+/CD25high+ Tregs, suggesting that higher Tregs may be associated with B-ALL, EBV positivity, or both (115).