Abbreviations: FES-RT, functional electrical stimulation resistance training; T, testosterone; TT, testosterone therapy; SCI, spinal cord injury; LTM, lean tissue mass; BMR, basal metabolic rate; REE, resting energy expenditure; HO, heterotopic ossification; GLUT4, glucose transporter type 4; Akt, protein kinase B; CSA, cross-sectional area; FIM, functional independence measure; TBI, traumatic brain injury; QTaVI, QT apex interval variability. The gene discussed is SLC2A4; the disease is brain injury.