The Shp-2 mutation blocks lymphopoiesis at the precursor stage.

Thymocytes were stained with anti-LY9.1 and anti–THY-1, and bone marrow cells were stained with anti-LY9.1 and anti-B220 and analyzed by flow cytometry. Results from one Shp-2^+/−/Rag-2^−/− and one Shp-2^−/−/Rag-2^−/− chimera are shown. Four Shp-2^−/−/Rag-2^−/− chimeric animals were examined, and consistent results were obtained.