Also tumor-specific mechanisms of pDC suppression are incompletely known, not only in terms of IR ligand expression, but also concerning the distribution of IRs on pDC subsets and the possibility of their simultaneous engagement: in vitro, the engagement of one single IR is sufficient to block pDC activation, but no studies so far addressed the result of multiple engagement nor any possible hierarchical relationship among IRs. The gene discussed is PDC; the disease is neoplasm.