Further experimental validation was performed in the Validation cohort B for α2M and LCAT, which were significantly increased in the infection group within the Validation cohort A. As revealed, the expression of α2M in the infection group was significantly higher than that in the control (FC = 1.70, p < 0.05), STH (FC = 1.54, p < 0.01) and non-UTI groups (FC = 1.45, p < 0.05), with no significant difference compared to the UTI group (FC = 1.04) (Fig 6A). Here, A2M is linked to infection.