Inclusion Criteria

- INCLUSION CRITERIA:

1. Male and female subjects of all ages and racial groups will be included. The
lower age limit will be determined by the ability to cooperate with saliva
collection methods: i.e. 6 months to 100 years old.

2. Patients will be recruited from current NIH Clinical Center pools or the outside
community. Patients must be diagnosed with cystinosis, sarcoidosis, head and
neck cancer, Sjogren's syndrome or diabetes by their institute physician.
Controls will be recruited from various NIH populations who are generally
healthy and without one of the diseases listed above or through the NIH Healthy
Volunteer Program.

3. Patients with both benign and malignant disease undergoing bone marrow
transplant or hematopoeitic stem cell transplant will be eligible. Among
patients with malignant disease both solid tumors and leukemias will be
included. Patients who can be diagnosed unequivocally with GVHD via biopsy of
the affected organ system will be included in the disease group. Patients will
be included in control group when GVHD can be reliably excluded.

4. For caries studies, we will examine salivary samples already collected from a
large twin cohort study in Brazil. These samples were collected from twins and
their siblings as part of a study of early childhood caries. Results from that
study suggest that genetics has a role in the development of caries. Whole
salivary samples have been collected and frozen for further analysis. These
samples will be examined for differences in salivary proteins which may be
associated with the development of early childhood caries. Samples are coded
with a unique numerical identifier with clinical diagnosis for caries, as well
as subject age, gender and ethnicity. No other patient information is linked to
this identifier to ensure patient confidentiality.

EXCLUSION CRITERIA:

1. Patients receiving autologous HCT or peripheral stem cell transplants.

2. Patients unable to cooperate with saliva collection.

3. Controls with a medical history or laboratory findings consistent with Sjogren's
syndrome, sarcoidosis, diabetes, or generally poor health, or controls taking
medications known to alter salivary protein profiles.