HGF and amyotrophic lateral sclerosis: Yamane et al. reported that it is important to maintain the concentration and location of HGF in the injured spinal cord [66], and our previous pharmacokinetic studies in cynomolgus monkeys and in a human phase I clinical trial for ALS reveal that continual intrathecal injections can directly control and maintain the therapeutic dose of intrathecal rhHGF [30].