NCT02834013 (DART: Dual Anti-CTLA-4 and Anti-PD-1 Blockade in Rare Tumors) is a Phase 2 study evaluating the effects of nivolumab plus ipilimumab (arm I) versus nivolumab alone (arm II) in patients with rare solid tumours (94 listed histotypes, including PC). The gene discussed is CTLA4; the disease is pachyonychia congenita.