In our case the patient suffered from a combined immunodeficiency due to mutations in DOCK8 known for difficulties in the control of certain viral infections, so that even the blocking of PD1-mediated inhibition may have not been sufficient to overcome the T-cell deficiency which are also known to have a migratory defect in DOCK8-deficient patients, uncurable by checkpoint blockade. This evidence concerns the gene PDCD1 and viral infectious disease.