ABOUT THE COVER
Abemaciclib, a cyclin-dependent kinase 4 and 6 dual inhibitor, was recently approved for the treatment of breast cancer. However, diarrhea is a common adverse event observed in patients treated with abemaciclib. Therefore, Thibault and colleagues sought to determine if toxicity was due to CDK4/6 inhibition or instead due to secondary pharmacological targets. Shown is an image of in situ hybridization (ISH) of rats administered 120 mg/kg abemaciclib using brown reagent with hematoxylin (blue) background. The representative section demonstrated an increased number of crypt cells staining for Smoc2, consistent and proportional to the elongation of the crypts in rats administered abemaciclib. For details, see article on page 257.