造血干细胞产生两种主要的祖细胞系：髓样祖细胞(myeloid progenitor)和淋巴样祖细胞(lymphoid progenitor)。图片来自：Regenerative Medicine. Department of Health and Human Services. Chapter 2: Bone Marrow (Hematopoietic) Stem Cells. August 20
