Taken together, our results suggest that ALL constitutes an important tool to study differences in O-glycans on CD4+ T cells with a regulatory-like phenotype, these CD4+ T cells are enriched NnTregs or recently activated Tregs expressing galactose-N-acetylgalactosamine and N-acetylgalactosamine. The gene discussed is CD4; the disease is acute lymphoblastic leukemia.