A critical review of the classic, as wells as most recent-and quite seminal-findings concerning the phenotypic and molecular characteristics of both fetal and neonatal B and T cells, the cells that mediate antibody and cellular immune responses in newborns and infants. Dr. Bona shows how the antibody response of neonates is modulated by maternal antibodies and how, in certain cases, this can cause transient or life-threatening neonatal autoimmune...