On 2016 Mar 15, Amanda Capes-Davis commented:

More than 600 articles have been published from 2000 to 2015 that refer to the KB cell line as "oral" or "epidermoid" (squamous cell carcinoma), when it is actually HeLa and thus derived from cervical adenocarcinoma. This is the first time I have seen a retraction or correction published in response. I would like to acknowledge the authors, editor Sergio Schenkman and publisher John Wiley & Sons Ltd for their integrity in correcting the scientific record.

Two points just for clarity.

1) The comment that KB is a "Human Oral Epidermal-like Cancer cell line" may cause confusion. More than 50 years of testing, starting with the work of Stanley Gartler in the 1960s, shows that KB is derived from HeLa. HeLa has been extensively described and we can be confident that it is cervical carcinoma. In the early stages of cross-contamination a mixed culture can occur, in which the original cells are present alongside the contaminating cells, resulting in a mixed phenotype. Typically this only lasts for a few passages; the faster growing culture will rapidly overgrow and replace the other population (Nims et al, 1998, PMID 9542633). Where HeLa is the contaminant it will typically outcompete other cell types, due to its higher rate of proliferation and resilience at low density. There is no evidence that KB is currently a mixed culture, or that it retains any characteristics from the original culture that were present before cross-contamination occurred.

2) There is ongoing confusion in the literature regarding expression of tissue-specific markers in misidentified cell lines. Phenotype can appear to support the idea that original material is still present. This has been debated in the literature since at least the 1970s - for an example, see the discussion between R.S. Chang and Walter Nelson-Rees regarding the Chang liver cell line (PMID 622561). "Chang liver" is actually HeLa despite the fact that it has been documented as expressing liver-specific markers. For this reason, it is essential to use genotype-based methods when looking at cell line origin. Cytogenetic analysis, short tandem repeat (STR) profiling and single nucleotide polymorphism (SNP) analysis are all important testing methods for cell line authenticity; STR profiling provides a consensus method for laboratories to compare results. Phenotype can provide helpful supporting evidence, but should not be the deciding factor when determining the origin of a cell line.

On 2016 Mar 15, Amanda Capes-Davis commented:

More than 600 articles have been published from 2000 to 2015 that refer to the KB cell line as "oral" or "epidermoid" (squamous cell carcinoma), when it is actually HeLa and thus derived from cervical adenocarcinoma. This is the first time I have seen a retraction or correction published in response. I would like to acknowledge the authors, editor Sergio Schenkman and publisher John Wiley & Sons Ltd for their integrity in correcting the scientific record.

Two points just for clarity.

1) The comment that KB is a "Human Oral Epidermal-like Cancer cell line" may cause confusion. More than 50 years of testing, starting with the work of Stanley Gartler in the 1960s, shows that KB is derived from HeLa. HeLa has been extensively described and we can be confident that it is cervical carcinoma. In the early stages of cross-contamination a mixed culture can occur, in which the original cells are present alongside the contaminating cells, resulting in a mixed phenotype. Typically this only lasts for a few passages; the faster growing culture will rapidly overgrow and replace the other population (Nims et al, 1998, PMID 9542633). Where HeLa is the contaminant it will typically outcompete other cell types, due to its higher rate of proliferation and resilience at low density. There is no evidence that KB is currently a mixed culture, or that it retains any characteristics from the original culture that were present before cross-contamination occurred.

2) There is ongoing confusion in the literature regarding expression of tissue-specific markers in misidentified cell lines. Phenotype can appear to support the idea that original material is still present. This has been debated in the literature since at least the 1970s - for an example, see the discussion between R.S. Chang and Walter Nelson-Rees regarding the Chang liver cell line (PMID 622561). "Chang liver" is actually HeLa despite the fact that it has been documented as expressing liver-specific markers. For this reason, it is essential to use genotype-based methods when looking at cell line origin. Cytogenetic analysis, short tandem repeat (STR) profiling and single nucleotide polymorphism (SNP) analysis are all important testing methods for cell line authenticity; STR profiling provides a consensus method for laboratories to compare results. Phenotype can provide helpful supporting evidence, but should not be the deciding factor when determining the origin of a cell line.