- Two thyroid hormone regulated genes, the beta-subunits of nerve growth factor (NGFB) and thyroid stimulating hormone (TSHB), are located less than 310 kb apart in both human and mouse genomes. Dracopoli, N.C., Rose, E., Whitfield, G.K., Guidon, P.T., Bale, S.J., Chance, P.A., Kourides, I.A., Housman, D.E. Genomics (1988)