This pencil drawing depicts two dividing budding yeast cells (top left) and fission yeast cells (bottom) that are imaginably being invaded by (from top) the Zika virus (ZIKV), the human immunodeficiency virus (HIV) and other viruses (image by Richard Y. Zhao and Jessica Qiu, University of Maryland School of Medicine, USA); image modified by MIC. The cover is published under the Creative Commons Attribution (CC BY) license.