 Gilbert’s terminology was widely accepted and it became clear that exons could be spliced together in alternative ways, thus multiplying the number of proteins that could be derived from a stretch of DNA. During the 1970s and 80s, further mechanisms of RNA processing were discovered in various organisms. For instance, mRNA could be generated by splicing together exons from several transcripts, from either the same or adjacent loci or even from different chromosomes (“trans-splicing”). Furthermore, RNA could be edited by changing several or single nucleotides, which could have large effects on the proteins translated from the mRNA. Mobile elements in the genome (transposons), already characterized by Barbara McClintock (1902–1992) in Maize in the early 1950s by classical genetic means, were also studied in bacteria and molecularly characterized around 1980 (Comfort 2001). It was not always immediately clear how general these and other mechanisms were (and it is still investigated). Nonetheless, it transpired that the notion that one gene, understood as an unequivocally localized stretch of DNA, corresponded to one polypeptide, had to be abandoned (Fogle 2000; Portin 2002).