At approximately day 1

CD7+ cells identified in yolk sac, neck, upper thorax and fetal liver.

Reference [PubMed Link]

Haynes BF, Martin ME, Kay HH, Kurtzberg J. 1988. Early events in human T cell ontogeny. J Exp Med 168:1061-1080.

At approximately day 1

CD7+ cells are concentrated in mesenchymal areas of upper fetal thorax regions.

Duration: 1 week

Reference [PubMed Link]

Haynes BF, Martin ME, Kay HH, Kurtzberg J. 1988. Early events in human T cell ontogeny. J Exp Med 168:1061-1080.