Table 1 Cell surface antigens expressed on AML compared with HSC

CD44

100%

(samples)

Mediates cell adhesion and can transduce signals

Ubiquitously expressed with many alternatively spliced isoforms

Cancer stem cell marker on several solid tumors

[123]

CD45RA

>90%

(samples)

Regulates a variety of cellular

processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation

naive T cells;

CD34⁺CD38⁺ normal progenitors

A specific marker for leukemia stem cell subpopulations in AML

[124]

CLL-1 (CLEC12A, DCAL-2, MICL)

≈95%

(samples)

ND

Restricted to hematopoietic cells of myeloid lineage

Expression may identify minimal residual disease and predict relapse

[81, 125, 126]

CD96

66%

(samples)

May have a function in NK cell adhesion and/or activation

Resting and activated T cells and NK cells, possibly intestinal epithelium

Expressed on only 5% of CD34⁺CD38⁻CD90⁺ cells in bone marrow

[127]

CD47

100%

(samples)

Binds SIRPa and inhibits phagocytosis

Widely expressed at low levels

Differential expression facilitated prospective separation of residual normal HSC from LSC

[128, 129]

CD32

34% (samples)

Fc-g receptor 2 (FCGR2)

Restricted to hematopoietic cells

Not expressed on functional HSC

[130]

CD25

25%

(samples)

High-affinity IL-2 receptor (IL2RA)

Restricted to hematopoietic cells

Not expressed on functional HSC

[130]

TIM-3

(HAVCR2)

most AML types (except for M3)

An important regulator of Th1 cell immunity and tolerance induction

Not expressed in CD34⁺CD38⁻ normal HSCs or the majority of CD34⁺CD38⁺ normal progenitors

An immune checkpoint, also a Th1-specific cell surface protein that regulates macrophage activation

[131–133]