The integrity of the genome is crucial for tumour suppression and for the propagation of genomic information to subsequent generations. DNA damage can result from cellular metabolism, exogenous genotoxic agents or routine errors in DNA replication and recombination. Cells have evolved mechanisms to maintain genome integrity.

Eukaryotic cells use motor proteins that move along cytoskeletal polymers to transport various intracellular cargos, including membranous organelles, protein complexes and mRNAs. In this article series, Nature Reviews Molecular Cell Biologywill highlight the progress made in understanding the function and regulation of different types of cytoskeletal motors.

Endocytic membrane trafficking involves the cellular internalization and sorting of extracellular molecules, plasma membrane proteins and lipids. Endocytosis is required for a vast number of functions, including nutrient uptake, cell adhesion and migration, receptor signalling, pathogen entry and cell polarity.

The articles in this series will focus on recent breakthroughs in our understanding of the mechanisms that govern the dynamic structural and spatial organization of chromatin, thereby providing important insights into gene regulation, DNA repair, development and epigenetic inheritance.

Cellular responses to mechanical forces drive morphogenesis, regulate normal physiology and contribute to pathogenesis of diverse diseases, from loss of hearing to muscular dystrophy and cancer.

Milestones in Cytoskeleton, presented by Nature, Nature Cell Biology and Nature Reviews Molecular Cell Biology, celebrates ground-breaking advances in cytoskeleton research over the past 60 years — from the discovery of actomyosin filaments in muscle to the identification of molecular motors, and from fluorescence analogue cytochemistry and differential interference contrast microscopy to single-molecule assays.

The regulation of gene expression beyond the level of transcription is much more intricate than previously thought, and involves diverse mechanisms that regulate the processing, stability and localization of RNA species. In this article series, Nature Reviews Molecular Cell Biologywill assess the basic mechanisms of post-transcriptional control and the interplay between them.

Cell polarity is crucial for the development of unicellular and multicellular organisms and is achieved through the coordinated actions of signalling pathways, membrane trafficking mechanisms and cytoskeletal dynamics.

Accompanying poster produced with support from Merck SeroNo. International S.A. There is an increasing appreciation of the versatility of lipids — from their role as essential membrane components to functions in membrane trafficking and signal transduction.

Recent breakthroughs in ageing research have shown that it is possible to slow ageing and extend the healthy lifespan of laboratory animals. Understanding the mechanisms that underlie the ageing process and ageing-related diseases will help us to develop approaches to delay their onset and progression and therefore improve the quality of human life.

Nature Reviews presents a Collection on microRNAs, which includes Reviews from Nature Reviews Genetics,Nature Reviews CancerandNature Reviews Molecular Cell Biology. The articles have been specially selected to provide an introduction to diverse aspects of microRNA biology, including their biogenesis, function in normal development and cancer, and evolutionary implications of their impact on gene regulation.

Stem-cell research is en vogue— 25 years after scientists first isolated mouse embryonic stem cells, it is now possible to isolate and culture stem cells from embryos and adult tissues of many species, including humans. Despite the rapid progress in this field, several important questions in the areas of embryonic and adult stem-cell research still remain unanswered. In a Series of specially commissioned articles, Nature Reviews Molecular Cell Biologyreports on the current hot and exciting topics in stem-cell research, discusses new technologies and resources to study stem cells and explores controversial issues, such as stem-cell ethics and funding.