<qa>  What is the name of the biopsy procedure that takes about 15 minutes?- Kidney biopsies at the beginning of the study, at 1, 6, 12, and 24 months, and then once a year for research purposes. Participants may refuse to have a research biopsy at any time during the study. Also, patients who are having a kidney biopsy for another reason at these time points will not have a second biopsy. The biopsy procedure takes about 15 minutes and is done in the hospital. The patient lies on his or her back and the skin over the transplanted kidney is cleaned with alcohol and iodine. The area is numbed with an injection of an anesthetic, and then a biopsy needle is placed through the kin. The biopsy may be repeated up to three times to get enough tissue to test for CAN. Patients lie flat for 4 hours after the procedure to reduce the risk of bleeding, and are observed for another 2 hours for possible complications. 