Disagreement about melanoma CSCs

The Evolving Science of Cancer Stem Cells by Carmen Phillips, NCI Cancer Bulletin 2010(Jul 27); 7(15). Excerpt:

Researchers from Stanford University earlier this month reported in Nature that they had found a marker, CD271, that identified a somewhat unique population of cells that could produce melanoma in highly immunocompromised mice; anywhere from 2.5 percent to 41 percent of cells in their human tumor samples expressed the marker. In additional experiments using similar mice on which human skin was engrafted, only tumor cells with the marker could produce tumors and metastases in the mice. (In his lab, Dr. Morrison noted, the same marker did not differentiate tumor-forming from nontumor-forming cells.)

The publication about CD271 is: Human melanoma-initiating cells express neural crest nerve growth factor receptor CD271 by Alexander D Boiko and 11 colleagues, Nature 2010(Jul 1); 466(7302): 133-7. [PubMed citation].

Comments: The sentence: "In his lab, Dr. Morrison noted, the same marker did not differentiate tumor-forming from nontumor-forming cells" is noteworthy. Why the difference in results for CD271?

The publication by Boiko and co-authors was cited in a previous post to this blog, "Melanoma-initiating cells identified", dated July 1, 2010.

See also an earlier post to this blog, "Tumorigenic cells not rare in human melanoma", dated December 3, 2008.