NOX4 and systemic sclerosis: Using PCR data from our cohort as the validation set, Figures 5C, D demonstrated satisfactory diagnostic performance of NOX4 (AUC = 0.798, 95% CI: 0.679 – 0.917) and NEK6 (AUC = 0.812, 95% CI: 0.690 – 0.935) for SSc.