The article by Michael D. Fox and Michael Greicius discusses the clinical applications of resting-state functional connectivity (fcMRI) in brain imaging. fcMRI focuses on spontaneous modulations in the BOLD signal during resting conditions, providing a window into the brain's ongoing neural processing. This approach has shown promise in improving the clinical utility of fMRI by offering better signal-to-noise ratios, allowing for broader patient populations, and circumventing task-related confounds. The authors highlight the potential of fcMRI in identifying group differences in brain disease, obtaining diagnostic and prognostic information, and guiding invasive and non-invasive treatments. They also provide guidelines for studying clinical populations with fcMRI, emphasizing the importance of replication, control strategies, and data sharing. Finally, they discuss future directions, including technique development and multimodal investigations, to enhance the clinical applicability of fcMRI.The article by Michael D. Fox and Michael Greicius discusses the clinical applications of resting-state functional connectivity (fcMRI) in brain imaging. fcMRI focuses on spontaneous modulations in the BOLD signal during resting conditions, providing a window into the brain's ongoing neural processing. This approach has shown promise in improving the clinical utility of fMRI by offering better signal-to-noise ratios, allowing for broader patient populations, and circumventing task-related confounds. The authors highlight the potential of fcMRI in identifying group differences in brain disease, obtaining diagnostic and prognostic information, and guiding invasive and non-invasive treatments. They also provide guidelines for studying clinical populations with fcMRI, emphasizing the importance of replication, control strategies, and data sharing. Finally, they discuss future directions, including technique development and multimodal investigations, to enhance the clinical applicability of fcMRI.