 The post-genomic gene thus not only adds to the plurality of gene concepts, but it is also inherently pluralistic. Many new cellular processes have been discovered and found to be ubiquitous, such as frameshifting, antisense DNA transcription, alternative and trans-splicing, RNA editing, as well as an abundance of regulatory elements in DNA, and of DNA regions transcribed to non-coding, but functional RNA. This has created a situation in which no single or simple set of criteria can be formulated for when a sequence of DNA counts as a gene. While the classical molecular gene seemed to reestablish a one-one relation of genes and phenotypes on the molecular level (one gene – one polypeptide), the processes just mentioned can result in a situation where one gene identified through an ORF gives rise to various gene products (molecular phenotypes). One can thus speak of “molecular pleiotropy” (Burian 2004). Additionally, a given product might be synthesized from various genes (ORFs). Accordingly, a given stretch of DNA can belong to several genes identified more broadly as set of template resources for a product. Furthermore, the nature of these processes implies that the molecular phenotype is not determined by the DNA sequence but depends on a distributed and context-dependent interaction of many cellular and, ultimately, extracellular factors. Hence one can also speak of “molecular epigenesis” in this respect (Burian 2004).