Cystatin C With Glomerular Filtration Rate, Estimated (eGFR) Labcorp test 121265

This test measures the level of cystatin C, a protein produced by your cells, to calculate your estimated glomerular filtration rate (eGFR). Because cystatin C levels are not affected by muscle mass, this test helps evaluate kidney function more accurately in people where standard creatinine tests might be misleading.