Fig 1: Measurement of six selected marker protein levels using ELISA. Bar graphs demonstrate expression levels of six marker proteins, including IGFBP2, C7, B2M, ENO1, DCD, and KPRP. All experiments were repeated three times in at least triplicate (n = 5, Mann–Whitney U test for statistical analysis). *p < 0.05, **p < 0.01, ***p < 0.001.