Both CD24 and CD44 have been reported as putative markers for isolating colorectal cancer initiating cells or CCSCs [ 7, 8, 25].
We have recently shown that GARP, which is specifically expressed on Tregs and TNregs upon activation, is a useful marker for isolating highly pure activated Tregs [16].
Therefore, ALDH has been suggested as a marker for isolating normal stem cells and lately also CSCs from several tumour types (reviewed in [15]).
We have recently identified the cell surface molecule GARP as a highly specific marker for isolating recently activated Tregs, however GARP is not expressed on any resting Tregs [16], and thus is only useful in defining Tregs after activation.
Further studies are necessary to fully characterize at the cellular level their potential role in tissue integrity and regeneration, and the utility of prominin-1 as a cell surface marker for isolating these cells.
ALDHI is often expressed in cancer stem cells and has been used as a functional marker for isolating cancer stem cells [66].
To explore the potential of this marker for isolating subpopulations of normal epithelial cells from the adult virgin mouse mammary gland, we used flow cytometry to investigate CD24 expression in mouse mammary cell preparations.
ALDH1 protein expression was also found correlated with ALDH enzymatic activity (Jiang et al, 2009), a crucial point as ALDH enzyme activity can be used as a functional marker for isolating CSCs (Carpentino et al, 2009; Huang et al, 2009).
Figure 2 shows an unrooted tree of the phylogenetic relationships, derived from 5 of the 6 microsatellite markers, for the isolates from these 7 patients plus 18 A. fumigatus isolate controls.
Variations in the MIRU-VNTR copy number have predisposed these sequences to be used as efficient molecular markers for typing isolates of M. tuberculosis complex.
