Millions of people worldwide experience acute and chronic muscle injury, leading to a reduced quality of life. Adult skeletal muscle displays a remarkable capacity for regeneration through the fusion of myogenic progenitor cells (MuSCs) to form new myotubes. This process is supported by fibro-adipogenic progenitor cells (FAPs), however, depletion of FAPs leads to rapid muscle degeneration and impaired muscle regeneration. Preliminary single-nucleus RNA sequencing (snRNA-seq) data revealed a distinct population of "activated FAPs" that emerges during early injury recovery. Subsequent co-culture studies revealed that FAPs from injured muscle enhance MuSC myogenesis more than uninjured FAPs, suggesting that activated FAPs influence regeneration through secreted factors. This project uses a TurboID-based proximity labeling system to identify these factors, with emphasis on ADAM12 as a potential regulator of the observed effect.