B2M and chronic kidney disease: Cerezo I et al. found that the levels of B2M showed a fair relationship between patients’ mortality and the risk of CKD progression.26 Barton KT et al. reported that serum B2M is strongly associated with AKI and showed a graded increase with increasing severity of AKI.27 A meta-analysis of 23,318 individuals revealed that creatinine-based and eGFR equations incorporating BTP and B2M indicated declining kidney function with chronic kidney disease progression, especially after adjusting for risk factors, with optimal results from combined eGFR equations.28