Radiosensitivity of the fibroblasts of the patient with OS. Survival of fibroblasts after irradiation with 1, 3, or 6 Gy. Survival is calculated as percentage of cell count without irradiation (0 Gy). The patient's fibroblasts (♦) are compared with an age-matched healthy control (▵) and an ARTEMIS-deficient patient (RS-SCID; □). The OS patient's fibroblasts display the same irradiation sensitivity as the ARTEMIS-deficient control. Error bars indicate standard deviation.