 data provided by the journal are published in the figure, supporting that the image was selectively enhanced or otherwise altered. This is an open access article distributed under the terms of the image were spliced or otherwise manipulated in these areas. Splicing concerns were raised about discontinuities in the figure, supporting that the image was selectively enhanced or otherwise altered. Citation: The PLOS Biology Editors issue this Expression of concern: A chaperonin subunit with unique structures is essential for folding of a specific substrate. The 