Serum Cystatin C (Cys-C) levels were significantly higher in MG patients compared to HCs (MG vs. HCs, 0.99 ± 0.20 vs. 0.86 ± 0.12 mg/L, p = 2.26E-41, adjusted p = 1.18E-40), ranking as the most prominently elevated biomarker among all 363 molecules analyzed. This evidence concerns the gene CST3 and myasthenia gravis.