PDCD1 and familial pancreatic carcinoma: Tumor-infiltrating ILC2s (TILC2s) are predictive of long-term survival in patients with pancreatic cancer.76 TILC2s express significant levels of PD-1, and TILC2 density increases post-anti-PD-1 therapy.76 In an orthotopic model of pancreatic cancer, TILC2s adoptively transferred into ILC2-deficient hosts were partially responsible for the reduction in tumor burden post-anti-PD-1 therapy.76 In addition to ILC2s, ILC3s are also affected by checkpoint therapies.