Table 1.

Non-canonical programmed cell death 1 (PD-1) signaling in cancer cells

Cancer type	Biology effect	Potential implication in clinic	Ref
Human melanoma (tumor tissue, cell lines), mouse melanoma (cell lines)	Promoting tumorigenesis by activating mTOR signaling	Contribution of melanoma PD-1 to the efficacy of PD-1 blockade therapy	22
Human hepatoma (tumor tissue, cell lines), mouse hepatoma (cell lines)	Promoting tumorigenesis by activating mTOR signaling	Contribution of hepatoma PD-1 to the efficacy of PD-1 blockade therapy	131
Human pancreatic cancer (tumor tissue, cell lines)	Promoting proliferation of cancer cells by targeting CYR61/CTGF via hippo pathway	Pancreatic cancer cell-intrinsic PD-1 correlate with poor prognosis	132
Human NSCLC (tumor tissue, cell lines), mouse NSCLC (cell line, M109)	Inhibiting proliferation of NSCLC cells	Contribution of NSCLC-intrinsic PD-1 signaling to HPD during PD-1 blockade therapy	133
Human lung cancer (tumor tissue, cell lines), human CRC (cell lines)	Inhibiting proliferation of cancer cells by suppressing AKT and ERK signaling (lung cancer cells and CRC cells)	Contribution of cancer cell-intrinsic PD-1 signaling to HPD during PD-1 blockade therapy	21

CRC, colorectal cancer; HPD, hyperprogressive disease; NSCLC, non-small cell lung cancer.