Skeletal muscle is a highly adaptive tissue that changes with many physiological stimuli and is composed of many cell types. Upon muscle injury, the concerted action of these cells is required to proceed through the process of inflammation, extracellular matrix remodeling, and restoration of function. To uncover novel genes and molecular pathways important for skeletal muscle remodeling and regeneration, we used a mouse hindlimb unloading and reloading protocol, and performed transcriptomics analysis. This study focuses on the microprotein Mustn1 (Musculoskeletal embryonic nuclear protein 1, also known as Mustang), whose gene expression is increased in muscle at the onset of hindlimb reloading, exercise, and injury. We generated a whole-body Mustn1 knockout mouse model and performed proteomics analysis of muscle and aorta.