In a small early-phase study of anti-CEA-specific CAR T cells given concurrently with selective intra-hepatic radiotherapy (radio-embolisation) in patients with CEA-expressing liver metastases (predominately originating from colorectal and pancreatic cancer), there was evidence of a biological effect with a reduction in PD-L1 expression levels and IDO expression in the metastatic lesions after treatment and evidence of biochemical (CEA) response in all patients. The gene discussed is IDO1; the disease is familial pancreatic carcinoma.