 At the same time there is little or no evidence for protein expression for genes that have appeared since primates or that do not have any protein-like features or conservation. Based on our results we describe a set of 2,001 genes that have no protein features and poor conservation, or have ambiguous annotations in gene or protein databases.
<meaning-changed>  At the same time there is little or no evidence for protein expression for genes that have appeared since primates or that do not have any protein-like features or conservation. Based on our results we describe a set of 2,001 genes that have no protein features and poor conservation, or have ambiguous annotations in gene or protein databases.
 At the same time there is little or no evidence for protein expression for genes that have appeared since primates or that do not have any protein-like features or cross-species conservation. We identify 19 non-protein like features such as weak conservation, no protein-like features or ambiguous annotations in the major databases that are indicators of low peptide detection rates. We use these features to describe a set of 2,001 genes that have no protein features and poor conservation, or have ambiguous annotations in gene or protein databases.