Table 1 Early haematopoietic progenitors in the bone marrow and thymus

Multipotent, self-renewing HSC

Lin⁻SCA1⁺KIT^hiFLT3⁻ (LSKFLT3⁻)

• Found in the bone marrow

• IL-7Rα⁻CD34⁻CD44^hi (long-term HSCs)

• IL-7Rα⁻CD34⁺CD44^hi (short-term HSCs)

MPP (also known as LMPP and CMLP)

Lin⁻SCA1⁺KIT^hi FLT3⁺(LSKFLT3⁺)

• Found in the bone marrow

• IL-7Rα⁻CD44^hiVCAM1⁺ and IL-7Rα^−/lowCD44^hiVCAM1⁻ subsets

ELP

Lin⁻SCA1⁺KIT^hiFLT3⁺(LSKFLT3⁺)

• Found in the bone marrow

• A lymphoid-specified subset of MPPs that are RAG⁺CD44^hi and GFP⁺ in RAG–GFP reporter mice

L-selectin-expressing MPP (LSP)

Lin⁻SCA1⁺ KIT^hi L-selectin-expressing and THY1.1⁻ in THY1.1 strains of mice

• Found in the bone marrow

• An L-selectin-expressing subset of MPPs that are FLT3⁺CD44^hi

CLP

Lin⁻SCA1^lowAA4⁺IL-7Rα⁺KIT^low

• Found in the bone marrow

• FLT3⁺CD44^hi

CLP-2 (also known as pre-pro-B cell)

IL-7Rα⁺B220⁺CD19⁻KIT^−/low and human CD25⁺ in pTα-reporter mice

• Found in the bone marrow

• FLT3⁺CD43⁺CD44^hi

ETP

Lin^lowKIT^hiCD25⁻

• Found in the thymus

• IL-7Rα^−/low CD4^lowCD44^hiSCA1⁺

• FLT3⁺ and FLT3⁻ subsets

• CD24⁻ (also known as DN1a) and CD24⁺ (also known as DN1b) subsets

DN2 cell

Lin^lowCD25⁺KIT^hi

• Found in the thymus

• IL-7Rα⁺CD4^lowCD44^hi