The use of oils as a carrier for lipophilic drugs during intraperitoneal injection is a common practice in biomedical research, but their differential effects on the microenvironment of the injection site has not been studied. The cover depicts macrophages incubated with vegetal oil, which induces cell death by either apoptosis or pyroptosis depending on the oil used (blue, live cells; green, apoptotic cells; red, necrotic cells). The authors conclude that careful selection of carrier oils based on experimental context is critical to the proper interpretation of data derived from intraperitoneal injection models. For more information, see the Highlight on page 165 and the article on page 288.