Recently, Hanna et al. evaluated the relationship between body composition defined by CT scans and discordance between eGFRcr and eGFR on the basis of the serum level of cystatin C in 545 adult patients with cancer.28 Muscle and adipose tissue cross-sectional areas were measured at the third lumbar vertebral body level using a validated deep learning pipeline. Here, CST3 is linked to cancer.