
Cover A resequencing study of sequence variation in the prion protein gene (PRNP) uncovers a complex history of selection. In reference to the neurodegenerative disorders caused by the accumulation of the abnormal isoform of prion protein, the illustration depicts a neuron, with the people in its nucleus representing human genome variation. The two isoforms of the prion protein (normal and disease-causing) are also featured. (Cover illustration by Marta Soldevila. [For details, see Soldevila et al., pp. 231-239.])