Domain architecture of HMTs (panel A) and demethylases (panel B) involved in nuclear hormone signaling. The names of the various functional domains in A and B are illustrated in panel C. MLL, Mixed-lineage leukemia; MBD, methyl-CpG-binding domain; SANT, Swi3 (switching-defective protein 3), Ada2 (adaptor 2), N-CoR (nuclear receptor corepressor), TFIIIB (transcription factor IIIB).