Cover image

Cell-free DNA (cfDNA) in plasma is generally believed to consist of short fragments of DNA. Recently, a previously unexplored population of long cfDNA has been discovered. In this issue, Che et al. demonstrate that such long cfDNA molecules are preferentially originating from euchromatin. Furthermore, the amount of long cfDNA molecules appears to positively correlate with transcriptional activity. The cover art is a stylized version of Figure 1A of the paper by Che et al. The strip of land is drawn to mimic a chromosome ideogram, with white and dark areas representing euchromatin and heterochromatin, respectively. The tall buildings, built on white areas of the strip of land, represent the overrepresentation of long cfDNA. The lit windows of the buildings represent transcriptional activity. The dark reflections of the heterochromatin in the water represent the overrepresentation of short cfDNA. (Cover art using watercolor and colored pencils on paper by Carmen Ng, https://www.carmen-ng.com/, based on a concept from Dennis Lo. [For details, see Che et al., pp. 189–200.])