RT Journal Article SR Electronic T1 Control of Gene Expression JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 155 OP 156 DO 10.1136/jmg.14.2.155-a VO 14 IS 2 A1 D. J. Weatherall YR 1977 UL http://jmg.bmj.com/content/14/2/155.2.abstract AB