VOLUME 291 (2016) PAGES 17143–17164
PAGE 17159:
The Δ4,5 double bond was missing in two of the structures shown in Fig. 21 of both the Papers in Press and the published version of this manuscript (structures of 16α-hydroxyprogesterone and 21-hydroxyprogesterone). These oxidation products had already been identified in the work presented in Refs. 7 and 53, as cited, and had not been first identified in this work. This error has now been corrected and does not affect the results or conclusions of this work.