Tumour heterogeneity
Tumour heterogeneity describes the observation that different tumour cells can show distinct morphological and phenotypic profiles, including cellular morphology, gene
expression, metabolism, motility, proliferation, and metastatic potential. This phenomenon occurs both between tumours
(inter-tumour heterogeneity) and within tumours (intra-tumour heterogeneity). A
minimal level of intra-tumour heterogeneity is a simple consequence of the
imperfection of DNA replication: whenever a cell (normal or cancerous) divides, a few mutations are acquired leading to a diverse population of
cancer cells27.
