Inclusion Criteria:

- recipients of or candidates for organ transplantation or organ donors for recipients
under evaluation at Emory University or CHOA

- normal volunteers, including individuals without any known end-stage organ disease
who are not on any immunosuppressive medication, and individuals with conditions
requiring immunosuppression (i.e. dermatological diseases) that do not require
transplant therapies

- ability to understand the purposes and risks of the study and willingly give written
informed consent, or in the case of minors, ability to give minor assent (children
older than 5 years of age), in conjunction with written guardian consent

Exclusion Criteria:

- patients who fail to meet the criteria for transplantation or post-transplant
follow-up by Emory or Childrens Healthcare of Atlanta physicians

- Any condition that, in the opinion of the attending physician, would place the
patient at undue risk by participating. Specific conditions include but are not
limited to: anemia prohibitive of phlebotomy, coagulopathy or technical
considerations that would prevent acquisition of sufficient tissue on biopsy for
clinical use, or medical urgency preventing timely administration of the consenting
process.