Figure 1 of the previous section (Introduction) shows these multi-layered effector functions whereas Figure 2 illustrates the immunologic synapse with target tumor cells, resulting in the polarization and release of granzymes and perforin. Clear engagement of death receptors, e.g., TNF-related apoptosis-inducing ligand (TRAIL) and Fas-Ligand (FASL), initiating apoptosis is evident in the figure. Images also show inhibitory signals (control cytotoxic results, KIRs binding to MHC-I), and activating cues (NKG2D-MICA/B interaction) (15). Here, PRF1 is linked to neoplasm.