PDCD1LG2 and mastocytoma: We also evaluated the degranulation of KIR+ NKG2A+ PD-1+ CD56dim PF-NK cells in a reverse antibody-dependent cellular cytotoxicity (R-ADCC) assay using the murine FcγR+ P815 mastocytoma cell line (which is negative for PD-L1/PD-L2).