This document summarizes various methods for estimating glomerular filtration rate (GFR) using creatinine and other biomarkers. It discusses the Cockcroft-Gault equation developed in 1976, the Modification of Diet in Renal Disease (MDRD) study from 1999, and the Chronic Kidney Disease Epidemiology Collaboration (CKD EPI) equation from 2009. These equations use variables like creatinine, age, sex and race to estimate GFR. More recent methods estimate GFR using cystatin C levels. The document also reviews biomarkers for detecting acute kidney injury, including neutrophil gelatinase-associated lipocalin, kidney injury molecule 1, interleukin 18, and liver-type fatty acid binding