CST3 and kidney disorder: Comparison of post hoc estimates of IoCL and CrCL with eGFR using different equations, including Cockcroft‐Gault equation,3 CKD‐EPI 2021 (creatinine and cystatin C),25 CKD‐EPI 2012 (creatinine and cystatin C),26 CKD‐EPI 2021 (creatinine only), CKD‐EPI 2009 (creatinine only),27 and four‐variable modification of diet in renal disease (MDRD) equation,28 is presented in Figure1.