We propose to analyze the histone and chromatin modifications from several classes of patients: 1) patients bearing the diagnosis of lymphoid malignancies made or confirmed at the NIH. Solid tumors of the lymphoid system would constitute the major source of these tissues, however tissue samples from patients with malignant diagnoses that involve circulating malignant cells (Mycosis fungoides, Sezary syndrome, etc.) would also be appropriate for analysis; 2) non-malignant lymphoid tissue obtained for diagnostic purposes or normal lymphoid tissue obtained incidentally during surgery (in all cases only residual and surplus tissue will be used, only with the express approval of the appropriate clinical investigator(s). Primarily included among these tissues would be hyperplastic lymphoid tissue especially tonsils. Other hyperplastic and non-malignant lymph node samples showing proliferative responses or sinus histiocytosis would also be appropriate to compare with the malignant samples.