PDCD1 and neoplasm: Given the impact of TACS and phenotypic adaptation on altered immunogenicity and subsequent expected cancer escape, along with the ability of mesenchymal tumour cells to upregulate PD-1 (programmed cell death protein-1)/PD-L1 (programmed death ligand-1) expression by modulating certain pathways [53], we further explored how TACS-specific tumour evolution affects responsiveness to PD-1/PD-L1 inhibition and its subsequent impact on simulated survival.