Human HMG Family Genes encode ubiquitous non-histone HMG chromatin proteins originally named according to PAGE electrophoretic mobility, shared physical properties, and association with chromatin. Canonical HMG proteins are subdivided into 3 superfamilies with characteristic functional sequence motifs: HMGB (formerly HMG-1/-2), HMGN (formerly HMG-14/-17), and HMGA (formerly HMG-I/Y/C). DNA-binding HMG proteins appear to have roles in matrix stabilization, ssDNA protection, replication, and transcription that influence cell growth, proliferation, differentiation, and death. (NCI) [ ]