Colorectal cancer screening programmes have been ongoing for several years. As they have been implemented, colorectal cancer mortality has been decreasing steadily because more people with colorectal cancer at early stages have been found. However, when patients with colorectal cancer are discovered at a later stage, their five-year survival decreases dramatically. The objective of this research is to discover colorectal cancer at an early stage. Tumour heterogeneity is a term that describes the differences between the same types of tumours in different patients, as well as the differences between cancer cells within a tumour. Such differences are brought about by interactions between the tumour and the supportive tissue – or stroma – surrounding it, as well as the molecular mesh termed the extracellular matrix, and stress such as hypoxia and drug treatment. All of these factors can imbue tumours with distinct features and different sensitivities to conventional therapy. As such, what might prove to be an effective course of treatment for one patient could be ineffective in another. Tumour heterogeneity means therapeutic heterogeneity, and this is obviously a problem for medics trying to treat cancer – not to mention their patients. To address this issue, a group of researchers based at Taipei Medical University in Taiwan is studying the molecular mechanisms of tumour-host interactions during disease progression. The interaction between tumour and host is now known to be involved in reprogramming cell plasticity, local inflammation, host cell recruitment and constructing microenvironments that enable tumour progression. As such, it is increasingly being seen as a target for future therapeutics. Led by Dr Wei-Lun Hwang, the Taipei team wants to understand the impacts of pathological cell communication that results from tumour heterogeneity.