PDCD1 and neoplasm: In a cohort or 43 TNBC patients, in which the pretreatment bulk tumor transcriptional pattern was correlated to the outcome of anti–PD-1 therapy (39), baseline expression of either ACVRL1 alone, or of the gene signature for ACVRL1+ macrophages, was significantly higher in nonresponders (n = 27) versus responders (n = 16) (Figure 3, C and D), indicative of an immunosuppressive environment.