Up‐regulation of FoxP1 in adult skeletal muscle was sufficient to induce features of cachexia, including 15% reduction in body mass (P < 0.05), and a 16–27% reduction in skeletal muscle mass (P < 0.05) that was characterized by a 20% reduction in muscle fibre cross‐sectional area of type IIX/B muscle fibres (P = 0.020). This evidence concerns the gene FOXP1 and Cachexia.