While a multivariate analysis indicated a joint effect of AKI on both KLK1 excretion and urine KLK1 CpG methylation (Figure 5), elevated KLK1 methylation would be predicted to decrease KLK1 excretion in AKI, as occurs in early/incipient AKI (Figure 2). This evidence concerns the gene KLK1 and acute kidney injury.