title: Disentangling inborn and acquired immunity in human twins.
abstract: The human geneticist Archibald Garrod noted in 1931 that, "It is, of necessity, no easy matter to distinguish between immunity which is inborn and that which has been acquired" (The Inborn Factors in Disease). In this issue of Cell, Brodin et al. show that the heritability of blood counts rapidly decreases with age for the lymphoid subsets responsible for adaptive immunity, unlike cells from other hematopoietic lineages.
authors.affiliation: St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA; Howard Hughes Medical Institute, New York, NY, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Inserm U1163, Necker Hospital for Sick Children, Paris, France; Paris Descartes University, Imagine Institute, Paris, France; Pediatric Hematology and Immunology Unit, Necker Hospital for Sick Children, Paris, France. Electronic address: casanova@rockefeller.edu.
authors.forename: Jean-Laurent
authors.initials: JL
authors.lastname: Casanova
authors.affiliation: St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Inserm U1163, Necker Hospital for Sick Children, Paris, France; Paris Descartes University, Imagine Institute, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Abel
mesh_terms: D006801:Humans; D007109:Immunity; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic