The 2019 Nobel Prize in Physiology or Medicine was jointly awarded to William G. Kaelin Jr, Sir Peter J. Ratcliffe and Gregg L. Semenza “for their discoveries of how cells sense and adapt to oxygen availability”. Collectively, their research led to an understanding of the elegant mechanism cells use to respond to changes in oxygen levels, a fundamental process that underpins normal physiologic functioning and plays a critical role in several diseases, including cancer. Via a combination of oxygen-dependant targeted destruction of the Hypoxia Inducible Factor and modulation of gene expression, cells are equipped to survive in a fluctuating environment. This pioneering research helped pave the way towards a plethora of medications that target this pathway. In celebration of their success, we have featured some of their articles in this collection, which includes content from Oncogene, British Journal of Cancer, Pediatric Research, Gene Therapy, Cell Death and Disease, and the Journal of Human Hypertension.

Organised by the National Cancer Research Institute, which is a partnership of 19 cancer research funders, the NCRI Cancer Conference provides a platform for researchers, clinicians, people affected by cancer and industry representatives to come together to discuss, present and showcase high-quality research.

In this collection of papers, we highlight five aspects of the tumour microenvironment.

This collection of papers illustrates how a simple indicator of systemic inflammation based on neutrophilia and/or lymphocytopenia can provide prognostic information in a wide range of cancer types.

Radiotherapy is a key treatment modality in the clinical management of cancer. Advances in recent years have broadened the tool kit available to oncologists, including the development of proton beam therapy. With several proton beam centres opening globally, this high energy radiotherapy treatment is becoming increasingly accessible. Despite this, several questions remain around how to optimise delivery and support best clinical practice. This collection of articles explores some of the questions surrounding proton beam therapy and discusses recent advances in the delivery of radiotherapy.

Increasing Body Mass Index (BMI) is a growing problem from several perspectives. Although it is well known that tobacco smoking greatly increases cancer risk, today, a higher proportion of the global population is affected by increased BMI, and a developing body of evidence now supports the role played by BMI in the risk of a large number of different cancers.

This Special Edition on Immunotherapy contains a selection of articles, commissioned content and videos that provide valuable insight into immunotherapy design, stratification and toxicity management.

Organised by the National Cancer Research Institute, which is a partnership of 19 cancer research funders, the NCRI Cancer Conference provides a platform for researchers, clinicians, people affected by cancer and industry representatives to come together to discuss, present and showcase high-quality research.

The British Journal of Cancer publishes articles on a wide range of cancer research, including basic biology of therapeutic relevance, translational research, early- and late-phase trials, epidemiology, and precision medicine. Updated each month, our Editor's Pick showcases a curated selection of those articles which are stimulating the most interest via electronic communication and other methods. This Collection reflects the diversity, quality and relevance of the articles published in BJC. We hope you enjoy reading this Collection, and we welcome your correspondence on these studies.

Colorectal carcinoma (CRC) is a leading global cause of cancer death. Efforts to understand the drivers of CRC have uncovered several genetic determinants, but further work is needed to further elucidate its genetic aetiology, and to identify high risk individuals. Four new studies, supported by the European Cooperation in Science and Technology (COST) framework, are presented in this dedicated Collection on CRC cancer genetics. In the accompanying editorial, Luis Carvajal-Carmona (UC Davis, California) assesses their impact, and highlights the need for collaborative international research efforts to answer complex clinical questions.

To mark the launch of our new Cellular and Molecular Biology section in the British Journal of Cancer, we present a series of articles to highlight our best research and reviews in this area.

In this supplement, the authors comprehensively review molecular and clinical evidence underlying the evolution of poly (ADP-ribose) polymerase (PARP) inhibitors in a journey spanning 50 years, which culminates in the recent licensing approval of the first oral PARP inhibitor, olaparib (Lynparzat™), for BRCA-mutated high-grade serous ovarian cancer.