Richard A. Lockshin's 1963 PhD dissertation on cell death in insect metamorphosis was conducted under the supervision of Harvard insect physiologist Carroll M. Williams. Lockshin and Williams used this doctoral research as the basis for five articles, with the main title "Programmed Cell Death," that were published between 1964 and 1965 in the Journal of Insect Physiology. These articles examine the cytological processes, neuronal and endocrinal controls, and the influence of drugs on the mechanism of cell death observed in pupal muscle structures of the American silkmoth. Those muscle structures disappeared right after the completion of adult development. Several scientists have credited this series of articles as introducing the now standard term "programmed cell death." Among the five articles, "Endocrine Potentiation of the Breakdown of the Intersegmental Muscles of Silkmoths" (abbreviated hereafter as "Endocrine Potentiation") was published first and has been cited the most often. The article suggests that the endocrinal conditions at the beginning of the adult development are necessary, but not sufficient, for precisely scheduling three weeks later the cell death activities in the pupal intersegmental muscles of American silkmoths. The research was among the first to attempt to pinpoint the role of hormones in regulating cell death, a process integral to development.