Tumour heterogeneity represents an ongoing challenge in the field of cancer therapy. Heterogeneity is evident between cancers from different patients and within a single tumour. The latter includes phenotypic diversity such as cell surface markers, (epi)genetic abnormality, growth rate, apoptosis and other hallmarks of cancer that eventually drive disease progression and treatment failure. Cancer stem cells (CSCs) have been put forward to be one of the non-genetic determining factors that contribute to intra-tumour heterogeneity. 

In this 9th edition of Medicine at the Crick, we will review our current understanding of Cancer Stem Cells, their role in initiation, progression and chemoresistance. We will also discuss new therapeutic avenues to eradicate these cells.