The image on the cover of Advanced Photonics Volume 1, Issue 6, exemplifies a label-free, motion-free intensity diffraction tomography technique utilizing programmable annular illumination to rapidly characterize large-volume three-dimensional refractive index distributions of C. elegans in vitro. Provided by J. Li et al., researchers from Nanjing University of Science and Technology and Boston University, the image is based on the research presented in their article, “High-speed in vitro intensity diffraction tomography,” Adv. Photon. 1(6) 066004, doi 10.1117/1.AP.1.6.066004).