Outlined are key trials that have been associated with the TRACERx project. Top, the MERMAID-1 trial incorporates bespoke ctDNA panels as MRD detection, following on from the work by Abbosh et al (52). Left, the THETIS and CHIRON trials are first-in-man studies that look at the efficacy of autologous clonal neoantigen reactive T cells in non-small cell lung cancer and melanoma. Clonal neoantigens are identified following tumour sequencing. T cells are subsequently expanded with neo-antigenic peptides and returned to the patient. Right, the DARWIN-II trial investigates the impact of intra-tumour heterogeneity in targeted therapy response in relapsed non small cell lung cancer, combining data from primary tumours sampled in the TRACERx Lung project.