MicroRNAs (miRNA) exert essential functions in mammalian development and physiology. The authors review recent insights from the phenotypic analysis of miRNA knockouts in mice that emphasize roles for these non-coding RNAs at different developmental stages and in adults, and illustrate the importance of functional miRNA targets, miRNA dosage, miRNA interactions and cellular context.

Shadow enhancers regulate a common target gene and drive expression patterns that overlap spatiotemporally. The authors review recent insights into the prevalence and role of shadow enhancers in metazoans, as well as their mechanisms of action to fine-tune gene expression. They also discuss the evolution of shadow enhancers and their implication in disease.

Africa is a continent with deep evolutionary history, which has implications for the genetic underpinnings of disease. In this Review, the authors discuss how genetic features of African populations provide both challenges and opportunities for understanding disease genetics in Africa. They describe how this genetic knowledge — combined with initiatives including capacity-building, data sharing and increased representation of African genomes in genetic variation databases — can be leveraged towards achieving precision medicine approaches in African healthcare.

Our evolutionary history has resulted in highly complex and sophisticated human physiology. Yet evolutionary footprints have also left us prone to diseases. In this Review, the authors discuss how events from the earliest history of life on Earth through to modern human evolution influence many disease traits and outcomes. They describe how an understanding and application of evolutionary frameworks can inform precision medicine initiatives.