In particular, a recent targeted MRM-based analysis of 72 plasma samples from patients with CKD confirmed a significant association of the AMBP protein, beta-2-microglobulin (B2M), lysozyme C (LYZ), hemoglobin subunit beta (HBB), and pigment epithelium-derived factor (PEDF) with the estimated glomerular filtration rate (eGFR), and the estimation of absolute plasma concentrations of a combination of these markers provided a stronger association with the outcome of CKD than individual markers [31]. Here, B2M is linked to chronic kidney disease.