The topics are human lymphopoiesis and examination thereof via methods of single-cell analysis. Processes within lymphopoiesis will be discussed with focus on fate decisions. Moreover, single-cell techniques (chiefly flow and mass cytometry) will be descibed as well as algorithmic apporaches to analysing and interpreting complex datasets. Finally, lymphopoiesis for B-cells will be explored to a greater extent, with some discussion of abnormalities.