ANGPT2 and acute kidney injury: Causal mediation analysis detected a significant indirect effect for rs2920656 on AKI-SP2 that was mediated through plasma ANG-2 concentrations (βindirect, − 0.07 per allele; 95% CI -0.11, − 0.03; p = 0.001), which means the proportion of effect between rs2920656 and AKI-SP2 that is mediated by ANG-2 concentrations is 41.5%.