Therefore, the relationship between lymphatic invasion and PD-L1 overexpression can be considered to be mutually “parallel.” Also, consistent with another inference of this meta-analysis that the inhibition of the PD-1/PD-L1 signaling pathway in advanced colorectal cancer could achieve remarkable results, existing clinical trials have exhibited the high security and activity of the treatment with PD-1/PD-L1 immunocheckpoint inhibitors [32]. Here, PDCD1 is linked to colorectal cancer.