Cancer Cell International publishes articles on all aspects of cancer cell biology, originating largely from work using cell culture techniques.

Denys is the Chairman of BioMedES, an editing service for the biomedical professions, particularly for non-native English speakers. He is also President of the International Federation for Cell Biology. His interests are in the cell biology of cancer, cell cycle, primary cilia, and diffusion theory. Although retired from academic work since 2006, he continues to edit several journals, including the sister journals of CCI, viz. Cell Biology International and Cell Biology International Reports. He also edits Oncology News and was founding editor of Theoretical Biology and Medical Modelling, the second journal he started as an independent editor with BioMed Central, the first being CCI itself, one of the earliest of its kind from BioMed Central.