PRF1 and telomere syndrome: Contrarily, the plasma level of Arginase in STS patients (699.6 pg/mL, IQR: 91.5–3417, N = 20) was found to be negatively correlated, with statistical value, with PRF1 (Spearman r = -0.597, p = 0.0055), GZMB (Spearman r = -0.708, p = 0.0005), and KLRK1 (Spearman r = -0.487, p = 0.0293) (Figure 3F).