<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>Dear RELION-users, <br>
<br>
With RELION version 2.0.4, a bug was introduced wherein each
iteration of auto-refinement incorrectly used the same (identical)
half-set reconstruction for alignment of all data. A degree of
reference-bias is therefore present, with the effect that the
reported resolution is higher than should be under "gold-standard"
conditions. The FSC and reported resolution is still based on
comparing two half-set reconstructions built from completely
separate image data, but reconstructions are not entirely free
from over-fitting artifacts. <br>
<br>
<b>This bug only affects refinements using half-sets, all
classification results are unaffected and can be considered
entirely correct. </b><br>
<br>
In order to claim a so-called "gold-standard" resolution, versions
before and including 2.0.3, or version 2.1b1 (which is now
available at <a class="moz-txt-link-freetext"
href="https://github.com/3dem/relion">https://github.com/3dem/relion</a>)
should be used. <b>This is strongly recommended</b>. There are
also patches attached in case you require a specific version to
run refinement. To apply a patch, simply go to your downloaded
relion (github) directory and run <br>
</p>
<p><tt>git apply 2.<version>_AR.patch </tt><br>
</p>
<p>and then build and install. <br>
</p>
<p> We apologize for any inconvenience, but more importantly thank
the community for making us aware of any issues. In this
particular case Prof. Leonid Sazanov and Dr. Radostin Danev are
both to credit, making sure RELION continues to produce reliable
results.</p>
<p>Sincerely, <br>
</p>
Björn Forsberg
</body>
</html>