Fig. 1From: The role of tumour heterogeneity and clonal cooperativity in metastasis, immune evasion and clinical outcomeThe linear progression model versus the parallel progression model of tumour evolution. In the linear progression model (upper panel), late stage tumour cells disseminate and form metastases. In contrast, in the parallel progression model (lower panel), early tumour cells disseminate and form metastases alongside the primary tumour, and both primary tumour and metastases progress in parallel gaining multiple subclonal populationsBack to article page