Analysis of transcriptomic and proteomic data is also revealing pseudogenes that are potentially expressed. The GENCODE reference set aids such analysis since it is the only gene set to contain comprehensively manually annotated pseudogenes to the same level as protein and noncoding genes. We currently predict a total of around 10,000 pseudogenes within the human genome. Recent publications highlight the implications of pseudogenes as regulators of gene expression (Han et al. 2011) and specifically a role in tumor biology (Poliseno et al. 2010), and thus we will have to rethink the classification of pseudogenes as nonfunctional entities on the genome.
