Evolutionarily new sequences expressed in tumors

Earlier we suggested the concept of the positive evolutionary role of tumors. According to this concept, tumors provide conditions for the expression of evolutionarily new and/or sleeping genes in their cells. Thus, tumors are considered as evolutionary proving ground or reservoir of expression. To support this concept we have previously characterized in silico and experimentally a new class of human tumor-related transcribed sequences. In this article we describe results of further studies of previously described tumor-related sequences. The results of molecular phylogeny studies, Southern hybridization experiments and computational comparison with genomes of other species are presented. These results suggest that these previously described tumor-related human transcripts are also relatively evolutionarily new.