What is a gene? Perhaps a simple question, but no clear answer is given by geneticists. Although the concept of a gene has been shown to be much more complex than ‘a DNA sequence transcribed into RNA and translated into a single protein product’, scientists often ignore this complexity. For example, while the majority of human genes show differential splicing, expression analysis is typically performed in function of genes, not transcripts (PubMed for instance has more than 800,000 ‘gene expression’ papers but only around 2,000 ‘transcript expression’ papers). I do believe that most of the authors of these papers are not ignorant of the concept of alternative splicing, but rather that transcripts are harder to study because less is known about specific transcripts functions than about gene functions, and because transcript analysis used to be more challenging from a technological perspective.