What is the relation between gfr and ccr?

Unclear question: What is ccr? Serum creatinine levels provide an indication of gfr, usually reported as estimated gfr.

GFR and CCr: We use GFR as a measure of kidney function. The creatinine clearance or ccr is one of the most common ways we use to estimate the gfr. There are more accurate ways to measure gfr, but these are often time consuming and not practical to use.

New fad: The glomerular filtration rate is how much plasma passes through the glomerular capillaries each minute. Normal for an average-sized young adult is 120 ml/min. A true creatinine clearance is a measure of how many ml's of plasma are cleared of creatinine each minute, a fair measure of gfr, and much more realistic than the current fad of substituting a spot creatinine.