PDCD1 and gastrointestinal stromal tumor: By measuring the levels of p‐PI3K, p‐Akt and p‐6s, we confirmed that the PD‐1/PD‐L1 blockade could rescue exhausted CD8+ T cells via the PI3K/Akt/mTOR signalling pathway in GIST cells with high PD‐L1 expression.