Prothoracicotropic hormone
Prothoracicotropic hormone (PTTH) was the first insect hormone to be discovered. It was originally described simply as "brain hormone" by early workers such as Stefan Kopeć (1922) and Vincent Wigglesworth (1934), who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached. After a certain point the ligation had no effect and both sections of the insect would molt or pupate. However, implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause would induce molting or pupation. Thus, the brain was originally thought to be the source of the hormone that induces molting in insects.
Christine Jorgensen
Jorgensen was faced with a world that placed strong societal emphasis on adhering to gender binaries and strict notions of masculinity and femininity. When Jorgensen was first exposed to the book "The Male Hormone" in the 1940s, the same traditional ideas of masculinity were reinforced through its pages. As the book posed, masculinity could be restored to individuals by utilizing male hormones. It was then that Jorgensen realized that the attitudes of the book were not aligned with her personal experiences and questions about gender identity. She refused to dismiss her personal sentiments and questions as confusion about sexuality and began taking estrogen. The significance of Jorgensen choosing this path was one of the first stages of transgender identity being legitimized and explored as a subject for both Jorgensen and the American public. Jorgensen's highly publicized transition helped bring to light gender identity and shaped a new culture of more inclusive ideas and accepting notions about the subject.