PDCD1 and neoplasm: Although, we identified only one PD1 PROG with loss of IFNγ signaling, it was interesting to note that this tumor had low frequency of CD8+ T cells (14.4% of CD45+ cells; bottom quartile <29%), and the highest percentage of natural killer (NK) cells in our tumor dissociate panels (11% of the CD45+ cells; upper quartile >5%) (Fig. 3D).