OTC and ornithine carbamoyltransferase deficiency: Among five randomly selected hiPSC clones - differentiated into hiPSC-Heps - one clone expressed OTC protein, while the four remaining clones lacked OTC expression, supporting the patient's suspected diagnosis of OTCD.To conclude, we demonstrate that hiPSC technology is a powerful diagnostic tool to substantiate the suspected diagnosis of OTCD in patients lacking genetic confirmation.