In this study, we analyzed 20 genes mainly expressed in Treg and/or exhausted CD8+ T cells and identified five markers (CD39, CTLA-4, TIGIT, TIM-3, and TNFR2) overexpressed in the PBMC of pediatric patients with B-ALL. This evidence concerns the gene HAVCR2 and precursor B-cell acute lymphoblastic leukemia.