OPENING DOORS: JOAN STEITZ AND JENNIFER DOUDNA, TWO WOMEN OF THE RNA WORLD, a dual biography of Joan Steitz and Jennifer Doudna, two important molecular biologists, unfolds the changing rules for women of science in the twenty years between Steitzs and Doudnas graduate training and the twenty plus years that followed, a pivotal period for women in science in the US. The book opens with an overview chapter, then alternating chapters in which each of the two women first identify an interest in science, attend graduate school, decide to get married, delve into their research subjects, have problems and thrills with children, experience teaching, deal with scientific competition, and receive awards. Throughout the chapters, historical comparisons show how the situation changed greatly between their two debuts in science in the 1960s and the 1980s. Then OPENING DOORS provides predictions and prescriptions for increasing the number and well-being of women in science.