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 Here, B2M is linked to acute kidney injury.