CD8A and neoplasm: For example, tumor PD-L1 (tPD-L1) engagement with MIC PD-1 (m-PD-1) activates Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2) to antagonize type 1 IFN and STAT1 pathway to repress Cxcl9 and impair CD8+T cell recruitment to lung metastases [59].