Fig 1. The creation, distribution and literature of a cell line: A cultured sample of cells (blue cells) may produce an immortal cell line (red cells), sometimes announced in ‘an establishing paper’ (in white).

Cells may then be distributed to other researchers and reported in research papers, the ‘primary literature’. If misidentification of cells is reported in ‘a notifying paper’ (in red, bottom left), this may raise questions about the entire cell line (question marks) and the papers based on it, since misidentification commonly occurs at the source. Notifying papers should be reported to ICLAC, which will decide whether cell lines should be added to the ICLAC misidentified cell line register. Meanwhile, the contaminated primary literature is cited (dotted lines) by ‘secondary literature’, spreading the contamination further.