IFNG and Norrie disease: Compared with PB or BM Th1 (CD4+ IFN-γ+) cells frequencies in healthy controls (19.68 ± 7.38% or 17.61 ± 7.96%), there was an observable decrease in ND patients (3.15 ± 1.92% or 5.66 ± 4.72%; *P = 0.001 or *P = 0.02).