have reported that CTLA-4 is not the main factor associated with tumor invasion and metastasis, owing to the above-mentioned mechanism and the lack of evidence, which may be attributed to the fact that the CTLA-4-specific mAb ipilimumab only demonstrates appreciable efficacy for metastatic melanoma and is less effective for other metastatic tumors (1). Here, CTLA4 is linked to neoplasm.