PIK3CA and neoplasm: Together these findings suggest that by combining PI3K/mTORi with PD‐1i in the EMC041 PDX model, we not only promote tumour T‐cell infiltration but also revert T‐cell exhaustion and stimulate the clonal hyper‐expansion of a cytotoxic CD8+ T‐cell population supported by a clonally expanded CD4+ Th1 niche.