CST3 and cancer: After this position statement, a recent analysis by Fu et al. assessed the performance of multiple eGFR equations, including the EKFC equations, in a large cross-sectional cohort in Sweden, including a subgroup of 2668 patients with cancer.22 In this subgroup, both EKFC and 2021 CKD-EPI using both creatinine and cystatin C had similar performance, with P30 92.1 (91.1 to 93.2)% and 90.6 (89.4 to 91.8)%, respectively.