CASP3 and chronic kidney disease: First, this is a pilot study whose population consists of 25 CKD patients, five patients for each stage of CKD; second, we evaluated caspase-3 concentrations, whose role is fundamental in the execution pathway, therefore we are not able to indicate the specific apoptotic mechanism activated in this population of patients; third, we have not investigated the possible role of autophagy in the progression of CKD.